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AA23-025A: Protecting Against Malicious Use of Remote Monitoring and Management Software

US-CERT Security Alerts - Wed, 01/25/2023 - 09:55
Original release date: January 25, 2023 | Last revised: January 26, 2023
Summary

The Cybersecurity and Infrastructure Security Agency (CISA), National Security Agency (NSA), and Multi-State Information Sharing and Analysis Center (MS-ISAC) (hereafter referred to as the “authoring organizations”) are releasing this joint Cybersecurity Advisory (CSA) to warn network defenders about malicious use of legitimate remote monitoring and management (RMM) software. In October 2022, CISA identified a widespread cyber campaign involving the malicious use of legitimate RMM software. Specifically, cyber criminal actors sent phishing emails that led to the download of legitimate RMM software—ScreenConnect (now ConnectWise Control) and AnyDesk—which the actors used in a refund scam to steal money from victim bank accounts.

Although this campaign appears financially motivated, the authoring organizations assess it could lead to additional types of malicious activity. For example, the actors could sell victim account access to other cyber criminal or advanced persistent threat (APT) actors. This campaign highlights the threat of malicious cyber activity associated with legitimate RMM software: after gaining access to the target network via phishing or other techniques, malicious cyber actors—from cybercriminals to nation-state sponsored APTs—are known to use legitimate RMM software as a backdoor for persistence and/or command and control (C2).

Using portable executables of RMM software provides a way for actors to establish local user access without the need for administrative privilege and full software installation—effectively bypassing common software controls and risk management assumptions.

The authoring organizations strongly encourage network defenders to review the Indicators of Compromise (IOCs) and Mitigations sections in this CSA and apply the recommendations to protect against malicious use of legitimate RMM software.

Download the PDF version of this report: pdf, 608 kb.

For a downloadable copy of IOCs, see AA23-025.stix (STIX, 19 kb).

Technical DetailsOverview

In October 2022, CISA used trusted third-party reporting, to conduct retrospective analysis of EINSTEIN—a federal civilian executive branch (FCEB)-wide intrusion detection system (IDS) operated and monitored by CISA—and identified suspected malicious activity on two FCEB networks:

  • In mid-June 2022, malicious actors sent a phishing email containing a phone number to an FCEB employee’s government email address. The employee called the number, which led them to visit the malicious domain, myhelpcare[.]online.
  • In mid-September 2022, there was bi-directional traffic between an FCEB network and myhelpcare[.]cc.

Based on further EINSTEIN analysis and incident response support, CISA identified related activity on many other FCEB networks. The authoring organizations assess this activity is part of a widespread, financially motivated phishing campaign and is related to malicious typosquatting activity reported by Silent Push in the blog post Silent Push uncovers a large trojan operation featuring Amazon, Microsoft, Geek Squad, McAfee, Norton, and Paypal domains.

Malicious Cyber Activity

The authoring organizations assess that since at least June 2022, cyber criminal actors have sent help desk-themed phishing emails to FCEB federal staff’s personal, and government email addresses. The emails either contain a link to a “first-stage” malicious domain or prompt the recipients to call the cybercriminals, who then try to convince the recipients to visit the first-stage malicious domain. See figure 1 for an example phishing email obtained from an FCEB network.

 

 

The recipient visiting the first-stage malicious domain triggers the download of an executable. The executable then connects to a “second-stage” malicious domain, from which it downloads additional RMM software.

CISA noted that the actors did not install downloaded RMM clients on the compromised host. Instead, the actors downloaded AnyDesk and ScreenConnect as self-contained, portable executables configured to connect to the actor’s RMM server.

Note: Portable executables launch within the user’s context without installation. Because portable executables do not require administrator privileges, they can allow execution of unapproved software even if a risk management control may be in place to audit or block the same software’s installation on the network. Threat actors can leverage a portable executable with local user rights to attack other vulnerable machines within the local intranet or establish long term persistent access as a local user service.

CISA has observed that multiple first-stage domain names follow naming patterns used for IT help/support themed social-engineering, e.g., hservice[.]live, gscare[.]live, nhelpcare[.]info, deskcareme[.]live, nhelpcare[.]cc). According to Silent Push, some of these malicious domains impersonate known brands such as, Norton, GeekSupport, Geek Squad, Amazon, Microsoft, McAfee, and PayPal.[1] CISA has also observed that the first-stage malicious domain linked in the initial phishing email periodically redirects to other sites for additional redirects and downloads of RMM software.

Use of Remote Monitoring and Management Tools

In this campaign, after downloading the RMM software, the actors used the software to initiate a refund scam. They first connected to the recipient’s system and enticed the recipient to log into their bank account while remaining connected to the system. The actors then used their access through the RMM software to modify the recipient’s bank account summary. The falsely modified bank account summary showed the recipient was mistakenly refunded an excess amount of money. The actors then instructed the recipient to “refund” this excess amount to the scam operator.
Although this specific activity appears to be financially motivated and targets individuals, the access could lead to additional malicious activity against the recipient’s organization—from both other cybercriminals and APT actors. Network defenders should be aware that:

  • Although the cybercriminal actors in this campaign used ScreenConnect and AnyDesk, threat actors can maliciously leverage any legitimate RMM software.
  • Because threat actors can download legitimate RMM software as self-contained, portable executables, they can bypass both administrative privilege requirements and software management control policies.
  • The use of RMM software generally does not trigger antivirus or antimalware defenses.
  • Malicious cyber actors are known to leverage legitimate RMM and remote desktop software as backdoors for persistence and for C2.[2],[3],[4],[5],[6],[7],[8]
  • RMM software allows cyber threat actors to avoid using custom malware.

Threat actors often target legitimate users of RMM software. Targets can include managed service providers (MSPs) and IT help desks, who regularly use legitimate RMM software for technical and security end-user support, network management, endpoint monitoring, and to interact remotely with hosts for IT-support functions. These threat actors can exploit trust relationships in MSP networks and gain access to a large number of the victim MSP's customers. MSP compromises can introduce significant risk—such as ransomware and cyber espionage—to the MSP’s customers.

The authoring organizations strongly encourage network defenders to apply the recommendations in the Mitigations section of this CSA to protect against malicious use of legitimate RMM software.

INDICATORS OF COMPROMISE

See table 1 for IOCs associated with the campaign detailed in this CSA.

Table 1: Malicious Domains and IP addresses observed by CISA

Domain

Description

Date(s) Observed

win03[.]xyz

Suspected first-stage malware domain

June 1, 2022

July 19, 2022

myhelpcare[.]online

Suspected first-stage malware domain

June 14, 2022

 

win01[.]xyz

Suspected first-stage malware domain

August 3, 2022

August 18, 2022

myhelpcare[.]cc

Suspected first-stage malware domain

September 14, 2022

247secure[.]us

Second-stage malicious domain

October 19, 2022

November 10, 2022

 

Additional resources to detect possible exploitation or compromise:

Mitigations

The authoring organizations encourage network defenders to:

  • Implement best practices to block phishing emails. See CISA’s Phishing Infographic for more information.
  • Audit remote access tools on your network to identify currently used and/or authorized RMM software.
  • Review logs for execution of RMM software to detect abnormal use of programs running as a portable executable.
  • Use security software to detect instances of RMM software only being loaded in memory.
  • Implement application controls to manage and control execution of software, including allowlisting RMM programs.
  • Require authorized RMM solutions only be used from within your network over approved remote access solutions, such as virtual private networks (VPNs) or virtual desktop interfaces (VDIs).
  • Block both inbound and outbound connections on common RMM ports and protocols at the network perimeter. 
  • Implement a user training program and phishing exercises to raise awareness among users about the risks of visiting suspicious websites, clicking on suspicious links, and opening suspicious attachments. Reinforce the appropriate user response to phishing and spearphishing emails.
RESOURCES
  • See CISA Insights Mitigations and Hardening Guidance for MSPs and Small- and Mid-sized Businesses for guidance on hardening MSP and customer infrastructure.
  • U.S. Defense Industrial Base (DIB) Sector organizations may consider signing up for the NSA Cybersecurity Collaboration Center’s DIB Cybersecurity Service Offerings, including Protective Domain Name System (PDNS) services, vulnerability scanning, and threat intelligence collaboration for eligible organizations. For more information on how to enroll in these services, email dib_defense@cyber.nsa.gov.
  • CISA offers several Vulnerability Scanning to help organizations reduce their exposure to threats by taking a proactive approach to mitigating attack vectors. See cisa.gov/cyber-hygiene-services.
  • Consider participating in CISA’s Automated Indicator Sharing (AIS) to receive real-time exchange of machine-readable cyber threat indicators and defensive measures. AIS is offered at no cost to participants as part of CISA’s mission to work with our public and private sector partners to identify and help mitigate cyber threats through information sharing and provide technical assistance, upon request, that helps prevent, detect, and respond to incidents.
PURPOSE

This advisory was developed by CISA, NSA, and MS-ISAC in furtherance of their respective cybersecurity missions, including their responsibilities to develop and issue cybersecurity specifications and mitigations.

DISCLAIMER

The information in this report is being provided “as is” for informational purposes only. CISA, NSA, and MS-ISAC do not endorse any commercial product or service, including any subjects of analysis. Any reference to specific commercial products, processes, or services by service mark, trademark, manufacturer, or otherwise, does not constitute or imply endorsement, recommendation, or favoring.

References Revisions
  • January 25, 2023: Initial Version

This product is provided subject to this Notification and this Privacy & Use policy.

Categories: Security Alerts

AA22-335A: #StopRansomware: Cuba Ransomware

US-CERT Security Alerts - Thu, 12/01/2022 - 10:04
Original release date: December 1, 2022 | Last revised: January 5, 2023
Summary

Actions to take today to mitigate cyber threats from ransomware:

• Prioritize remediating known exploited vulnerabilities.
• Train users to recognize and report phishing attempts.
• Enable and enforce phishing-resistant multifactor authentication.

Note: This joint Cybersecurity Advisory (CSA) is part of an ongoing #StopRansomware effort to publish advisories for network defenders that detail various ransomware variants and ransomware threat actors. These #StopRansomware advisories include recently and historically observed tactics, techniques, and procedures (TTPs) and indicators of compromise (IOCs) to help organizations protect against ransomware. Visit stopransomware.gov to see all #StopRansomware advisories and to learn more about other ransomware threats and no-cost resources.

The FBI and the Cybersecurity and Infrastructure Security Agency (CISA) are releasing this joint CSA to disseminate known Cuba ransomware IOCs and TTPs associated with Cuba ransomware actors identified through FBI investigations, third-party reporting, and open-source reporting. This advisory updates the December 2021 FBI Flash: Indicators of Compromise Associated with Cuba Ransomware.

Note: While this ransomware is known by industry as “Cuba ransomware,” there is no indication Cuba ransomware actors have any connection or affiliation with the Republic of Cuba.

Since the release of the December 2021 FBI Flash, the number of U.S. entities compromised by Cuba ransomware has doubled, with ransoms demanded and paid on the increase.

This year, Cuba ransomware actors have added to their TTPs, and third-party and open-source reports have identified a possible link between Cuba ransomware actors, RomCom Remote Access Trojan (RAT) actors, and Industrial Spy ransomware actors.

FBI and CISA encourage organizations to implement the recommendations in the Mitigations section of this CSA to reduce the likelihood and impact of Cuba ransomware and other ransomware operations.

Download the PDF version of this report: pdf, 649 kb.

For a downloadable copy of IOCs, see:

Technical DetailsOverview

Since the December 2021 release of FBI Flash: Indicators of Compromise Associated with Cuba Ransomware, FBI has observed Cuba ransomware actors continuing to target U.S. entities in the following five critical infrastructure sectors: Financial Services, Government Facilities, Healthcare and Public Health, Critical Manufacturing, and Information Technology. As of August 2022, FBI has identified that Cuba ransomware actors have:

  • Compromised 101 entities, 65 in the United States and 36 outside the United States.
  • Demanded 145 million U.S. Dollars (USD) and received 60 million USD in ransom payments.
Cuba Ransomware Actors’ Tactics, Techniques, and Procedures

As previously reported by FBI, Cuba ransomware actors have leveraged the following techniques to gain initial access into dozens of entities in multiple critical infrastructure sectors:

  • Known vulnerabilities in commercial software [T1190]
  • Phishing campaigns [T1566]
  • Compromised credentials [T1078]
  • Legitimate remote desktop protocol (RDP) tools [T1563.002]

After gaining initial access, the actors distributed Cuba ransomware on compromised systems through Hancitor—a loader known for dropping or executing stealers, such as Remote Access Trojans (RATs) and other types of ransomware, onto victims’ networks.

Since spring 2022, Cuba ransomware actors have modified their TTPs and tools to interact with compromised networks and extort payments from victims.[1],[2]

Cuba ransomware actors have exploited known vulnerabilities and weaknesses and have used tools to elevate privileges on compromised systems. According to Palo Alto Networks Unit 42,[2] Cuba ransomware actors have:

  • Exploited CVE-2022-24521 in the Windows Common Log File System (CLFS) driver to steal system tokens and elevate privileges.
  • Used a PowerShell script to identify and target service accounts for their associated Active Directory Kerberos ticket. The actors then collected and cracked the Kerberos tickets offline via Kerberoasting [T1558.003].
  • Used a tool, called KerberCache, to extract cached Kerberos tickets from a host’s Local Security Authority Server Service (LSASS) memory [T1003.001].
  • Used a tool to exploit CVE-2020-1472 (also known as “ZeroLogon”) to gain Domain Administrative privileges [T1068]. This tool and its intrusion attempts have been reportedly related to Hancitor and Qbot.

According to Palo Alto Networks Unit 42, Cuba ransomware actors use tools to evade detection while moving laterally through compromised environments before executing Cuba ransomware. Specifically, the actors, “leveraged a dropper that writes a kernel driver to the file system called ApcHelper.sys. This targets and terminates security products. The dropper was not signed; however, the kernel driver was signed using the certificate found in the LAPSUS NVIDIA leak." [T1562.001].[2]

In addition to deploying ransomware, the actors have used “double extortion” techniques, in which they exfiltrate victim data, and (1) demand a ransom payment to decrypt it and, (2) threaten to publicly release it if a ransom payment is not made.[2]

Cuba Ransomware Link to RomCom and Industrial Spy Marketplace

Since spring 2022, third-party and open-source reports have identified an apparent link between Cuba ransomware actors, RomCom RAT actors, and Industrial Spy ransomware actors:

  • According to Palo Alto Networks Unit 42, Cuba ransomware actors began using RomCom malware, a custom RAT, for command and control (C2).[2]
  • Cuba ransomware actors may also be leveraging Industrial Spy ransomware. According to third-party reporting, suspected Cuba ransomware actors compromised a foreign healthcare company. The threat actors deployed Industrial Spy ransomware, which shares distinct similarities in configuration to Cuba ransomware. Before deploying the ransomware, the actors moved laterally using Impacket and deployed the RomCom RAT and Meterpreter Reverse Shell HTTP/HTTPS proxy via a C2 server [T1090].
  • Cuba ransomware actors initially used their leak site to sell stolen data; however, around May 2022, the actors began selling their data on Industrial Spy’s online market for selling stolen data.[2]

RomCom actors have targeted foreign military organizations, IT companies, food brokers and manufacturers.[3][4] The actors copied legitimate HTML code from public-facing webpages, modified the code, and then incorporated it in spoofed domains [T1584.001], which allowed the RomCom actors to:

  • Host counterfeit Trojanized applications for
    • SolarWinds Network Performance Monitor (NPM),
    • KeePass password manager,
    • PDF Reader Pro, (by PDF Technologies, Inc., not an Adobe Acrobat or Reader product), and
    • Advanced IP Scanner software;
  • Deploy the RomCom RAT as the final stage.
INDICATORS OF COMPROMISE

See tables 1 through 5 for Cuba ransomware IOCs that FBI obtained during threat response investigations as of late August 2022. In addition to these tables, see the publications in the References section below for aid in detecting possible exploitation or compromise.

Note: For IOCs as of early November 2021, see FBI Flash: Indicators of Compromise Associated with Cuba Ransomware.

Table 1: Cuba Ransomware Associated Files and Hashes, as of Late August 2022

File Name

File Path

File Hash

netping.dll

c:\windows\temp

SHA256: f1103e627311e73d5f29e877243e7ca203292f9419303c661aec57745eb4f26c

shar.bat

 

MD5: 4c32ef0836a0af7025e97c6253054bca

SHA256: a7c207b9b83648f69d6387780b1168e2f1eabd23ae6e162dd700ae8112f8b96c

Psexesvc.exe

 

SHA256: 141b2190f51397dbd0dfde0e3904b264c91b6f81febc823ff0c33da980b69944

1.bat

 

 

216155s.dll

 

 

23246s.bat

 

SHA256: 02a733920c7e69469164316e3e96850d55fca9f5f9d19a241fad906466ec8ae8

23246s.dll

 

SHA256: 0cf6399db55d40bc790a399c6bbded375f5a278dc57a143e4b21ea3f402f551f

23246st.dll

 

SHA256: f5db51115fa0c910262828d0943171d640b4748e51c9a140d06ea81ae6ea1710

259238e.exe

 

 

31-100.bat

 

 

3184.bat

 

 

3184.dll

 

 

45.dll

 

SHA256:

857f28b8fe31cf5db6d45d909547b151a66532951f26cda5f3320d2d4461b583

4ca736d.exe

 

 

62e2e37.exe

 

 

64.235.39.82

 

 

64s.dll

 

 

7z.sfx

 

 

7zCon.sfx

 

 

7-zip.chm

 

 

82.ps1

 

 

9479.bat

 

SHA256: 08eb4366fc0722696edb03981f00778701266a2e57c40cd2e9d765bf8b0a34d0

9479p.bat

 

SHA256: f8144fa96c036a8204c7bc285e295f9cd2d1deb0379e39ee8a8414531104dc4a

9479p.ps1

 

SHA256: 88d13669a994d2e04ec0a9940f07ab8aab8563eb845a9c13f2b0fec497df5b17

a.exe

 

 

MD5: 03c835b684b21ded9a4ab285e4f686a3

 

SHA1: eaced2fcfdcbf3dca4dd77333aaab055345f3ab4

 

SHA256: 0f385cc69a93abeaf84994e7887cb173e889d309a515b55b2205805bdfe468a3

 

SHA256: 0d5e3483299242bf504bd3780487f66f2ec4f48a7b38baa6c6bc8ba16e4fb605

 

SHA256: 7e00bfb622072f53733074795ab581cf6d1a8b4fc269a50919dda6350209913c

 

SHA256: af4523186fe4a5e2833bbbe14939d8c3bd352a47a2f77592d8adcb569621ce02

a220.bat

 

 

a220.dll

 

SHA256: 8a3d71c668574ad6e7406d3227ba5adc5a230dd3057edddc4d0ec5f8134d76c3

a82.exe

 

SHA256: 4306c5d152cdd86f3506f91633ef3ae7d8cf0dd25f3e37bec43423c4742f4c42

a91.exe

 

SHA256: 3d4502066a338e19df58aa4936c37427feecce9ab8d43abff4a7367643ae39ce

a99.exe

 

SHA256: f538b035c3de87f9f8294bec272c1182f90832a4e86db1e47cbb1ab26c9f3a0b

aa.exe

 

 

aa2.exe

 

 

aaa.stage.16549040.dns.alleivice.com

 

 

add2.exe

 

 

advapi32.dll

 

 

agent.13.ps1

 

 

agent.bat

 

SHA256: fd87ca28899823b37b2c239fbbd236c555bcab7768d67203f86d37ede19dd975

agent.dll

 

 

agent13.bat

 

 

agent13.ps1

 

SHA256: 1817cc163482eb21308adbd43fb6be57fcb5ff11fd74b344469190bb48d8163b

agent64.bin

 

SHA256: bff4dd37febd5465e0091d9ea68006be475c0191bd8c7a79a44fbf4b99544ef1

agsyst121.bat

 

 

agsyst121.dll

 

 

all.bat

 

SHA256: ecefd9bb8b3783a81ab934b44eb3d84df5e58f0289f089ef6760264352cf878a

all.dll

 

SHA256: db3b1f224aec1a7c58946d819d729d0903751d1867113aae5cca87e38c653cf4

anet.exe

 

SHA1: 241ce8af441db2d61f3eb7852f434642739a6cc3

 

SHA256: 74fbf3cc44dd070bd5cb87ca2eed03e1bbeec4fec644a25621052f0a73abbe84

 

SHA256: b160bd46b6efc6d79bfb76cf3eeacca2300050248969decba139e9e1cbeebf53

SHA256: f869e8fbd8aa1f037ad862cf6e8bbbf797ff49556fb100f2197be4ee196a89ae

App.exe

 

 

appnetwork.exe

 

 

AppVClient.man

 

 

aswSP_arPot2

 

 

aus.exe

 

SHA256: 0c2ffed470e954d2bf22807ba52c1ffd1ecce15779c0afdf15c292e3444cf674

SHA256: 310afba59ab8e1bda3ef750a64bf39133e15c89e8c7cf4ac65ee463b26b136ba

av.bat

 

SHA256: b5d202456ac2ce7d1285b9c0e2e5b7ddc03da1cbca51b5da98d9ad72e7f773b8

c2.ps1

 

 

c2.ps1

 

 

cdzehhlzcwvzcmcr.aspx

 

 

check.exe

 

 

checkk.exe

 

 

checkk.txt

 

SHA256: 1f842f84750048bb44843c277edeaa8469697e97c4dbf8dc571ec552266bec9f

client32.exe

 

 

comctl32 .dll

 

 

comp2.ps1

 

 

comps2.ps1

 

 

cqyrrxzhumiklndm.aspx

 

 

defendercontrol.exe

 

 

ff.exe

 

SHA256: 1b943afac4f476d523310b8e3afe7bca761b8cbaa9ea2b9f01237ca4652fc834

File __agsyst121.dll

 

 

File __aswArPot.sys

 

 

File __s9239.dll

 

 

File_agsyst121.dll

 

 

File_aswArPot.sys

 

 

File_s9239.dll

 

 

ga.exe

 

 

gdi32 .dll

 

 

geumspbgvvytqrih.aspx

 

 

IObit UNLOCKER.exe

 

 

kavsa32.exe

 

MD5: 236f5de8620a6255f9003d054f08574b

SHA1: 9b546bd99272cf4689194d698c830a2510194722

kavsyst32.exe

 

 

kernel32.dll

 

 

komar.bat

 

SHA256: B9AFE016DBDBA389000B01CE7645E7EEA1B0A50827CDED1CBAA48FBC715197BB

komar.dll

 

 

komar121.bat

 

 

komar121.dll

 

 

komar2.ps1

 

SHA256: 61971d3cbf88d6658e5209de443e212100afc8f033057d9a4e79000f6f0f7cc4

komar64.dll

 

SHA256: 8E64BACAF40110547B334EADCB0792BDC891D7AE298FBFFF1367125797B6036B

mfcappk32.exe

 

 

newpass.ps1

 

SHA256: c646199a9799b6158de419b1b7e36b46c7b7413d6c35bfffaeaa8700b2dcc427

npalll.exe

 

SHA256: bd270853db17f94c2b8e4bd9fa089756a147ed45cbc44d6c2b0c78f361978906

ole32.dll

 

 

oleaut32.dll

 

 

open.bat

 

SHA256: 2EB3EF8A7A2C498E87F3820510752043B20CBE35B0CBD9AF3F69E8B8FE482676

open.exe

 

 

pass.ps1

 

SHA256: 0afed8d1b7c36008de188c20d7f0e2283251a174261547aab7fb56e31d767666

pdfdecrypt.exe

 

 

powerview.ps1

 

 

prt3389.bat

 

SHA256: e0d89c88378dcb1b6c9ce2d2820f8d773613402998b8dcdb024858010dec72ed

ra.ps1

 

SHA256: 571f8db67d463ae80098edc7a1a0cad59153ce6592e42d370a45df46f18a4ad8

rg1.exe

 

 

Rg2.exe

 

 

rundll32

 

 

s64174.bat

 

SHA256: 10a5612044599128981cb41d71d7390c15e7a2a0c2848ad751c3da1cbec510a2

SHA256: 1807549af1c8fdc5b04c564f4026e41790c554f339514d326f8b55cb7b9b4f79

s64174.dll

 

 

s9239.bat

 

 

s9239.dll

 

 

shell32.dll

 

 

stel.exe

 

 

syskav64.exe

 

 

sysra64,exe

 

 

systav332.bat

 

SHA256: 01242b35b6def71e42cc985e97d618e2fabd616b16d23f7081d575364d09ca74

TC-9.22a.2019.3.exe

 

 

TeamViewer.exe

 

 

testDLL.dll

 

 

tug4rigd.dll

 

SHA256: 952b34f6370294c5a0bb122febfaa80612fef1f32eddd48a3d0556c4286b7474

UpdateNotificationPipeline.002.etl

 

 

user32.dll

 

 

v1.bat

 

 

v2.bat

 

 

v3.bat

 

 

veeamp.exe

 

SHA256: 9aa1f37517458d635eae4f9b43cb4770880ea0ee171e7e4ad155bbdee0cbe732

version.dll

 

 

vlhqbgvudfnirmzx.aspx

 

 

wininet.dll

 

 

wlog.exe

 

 

wpeqawzp.sys

 

 

y3lcx345.dll

 

 

zero.exe

 

SHA256: 3a8b7c1fe9bd9451c0a51e4122605efc98e7e4e13ed117139a13e4749e211ed0

 

 

 

 

 

 

 

Table 2: Cuba Ransomware Associated Email Addresses, as of Late August 2022

Email Provider

Email Addresses

Cuba-supp[.]com

admin@cuba-supp[.]com

Encryption-support[.]com

admin@encryption-support[.]com

Mail.supports24[.]net

inbox@mail.supports24[.]net

 

Table 3: Cuba Ransomware Associated Jabber Address, as of Late August 2022

cuba_support@exploit[.]im

 

Table 4: IP Addresses Associated with Cuba Ransomware, as of Late August 2022
Note: Some of these observed IP addresses are more than a year old. FBI and CISA recommend vetting or investigating these IP addresses prior to taking forward-looking action such as blocking.

193.23.244[.]244

144.172.83[.]13

216.45.55[.]30

94.103.9[.]79

149.255.35[.]131

217.79.43[.]148

192.137.101[.]46

154.35.175[.]225

222.252.53[.]33

92.222.172[.]39

159.203.70[.]39

23.227.198[.]246

92.222.172[.]172

171.25.193[.]9

31.184.192[.]44

10.13.102[.]1

185.153.199[.]169

37.120.247[.]39

10.13.102[.]58

192.137.100[.]96

37.44.253[.]21

10.133.78[.]41

192.137.100[.]98

38.108.119[.]121

10.14.100[.]20

192.137.101[.]205

45.164.21[.]13

103.114.163[.]197

193.34.167[.]17

45.32.229[.]66

103.27.203[.]197

194.109.206[.]212

45.86.162[.]34

104.217.8[.]100

195.54.160[.]149

45.91.83[.]176

107.189.10[.]143

199.58.81[.]140

64.52.169[.]174

108.170.31[.]115

204.13.164[.]118

64.235.39[.]82

128.31.0[.]34

209.76.253[.]84

79.141.169[.]220

128.31.0[.]39

212.192.241[.]230

84.17.52[.]135

131.188.40[.]189

213.32.39[.]43

86.59.21[.]38

141.98.87[.]124

216.45.55[.]3

 

 

Table 5: Cuba Bitcoin Wallets Receiving Payments, as of Late August 2022

bc1q4vr25xkth35qslenqwd7aw020w85qrvlrhv7hc

bc1q5uc0fdnz0ve5pg4nl4upa9ly586t6wmnghfe7x

bc1q6rsj3cn37dngypu5kad9gdw5ykhctpwhjvun3z

bc1q6zkemtyyrre2mkk23g93zyq98ygrygvx7z2q0t

bc1q9cj0n9k2m282x0nzj6lhqjvhkkd4h95sewek83

bc1qaselp9nhejc3safcq3vn5wautx6w33x0llk7dl

bc1qc48q628t93xwzljtvurpqhcvahvesadpwqtsza

bc1qgsuf5m9tgxuv4ylxcmx8eeqn3wmlmu7f49zkus

bc1qhpepeeh7hlz5jvrp50uhkz59lhakcfvme0w9qh

bc1qjep0vx2lap93455p7h29unruvr05cs242mrcah

bc1qr9l0gcl0nvmngap6ueyy5gqdwvm34kdmtevjyx

bc1qs3lv77udkap2enxv928x59yuact5df4t95rsqr

bc1qyd05q2m5qt3nwpd3gcqkyer0gspqx5p6evcf7h

bc1qzz7xweq8ee2j35tq6r5m687kctq9huskt50edv

bc1qvpk8ksl3my6kjezjss9p28cqj4dmpmmjx5yl3y

bc1qhtwfcysclc7pck2y3vmjtpzkaezhcm6perc99x

bc1qft3s53ur5uq5ru6sl3zyr247dpr55mnggwucd3

bc1qp7h9fszlqxjwyfhv0upparnsgx56x7v7wfx4x7

bc1q4vr25xkth35qslenqwd7aw020w85qrvlrhv7hc

bc1q5uc0fdnz0ve5pg4nl4upa9ly586t6wmnghfe7x

bc1q6rsj3cn37dngypu5kad9gdw5ykhctpwhjvun3z

bc1q6zkemtyyrre2mkk23g93zyq98ygrygvx7z2q0t

bc1q9cj0n9k2m282x0nzj6lhqjvhkkd4h95sewek83

bc1qaselp9nhejc3safcq3vn5wautx6w33x0llk7dl

bc1qc48q628t93xwzljtvurpqhcvahvesadpwqtsza

bc1qgsuf5m9tgxuv4ylxcmx8eeqn3wmlmu7f49zkus

bc1qhpepeeh7hlz5jvrp50uhkz59lhakcfvme0w9qh

bc1qjep0vx2lap93455p7h29unruvr05cs242mrcah

bc1qr9l0gcl0nvmngap6ueyy5gqdwvm34kdmtevjyx

bc1qs3lv77udkap2enxv928x59yuact5df4t95rsqr

bc1qyd05q2m5qt3nwpd3gcqkyer0gspqx5p6evcf7h

bc1qzz7xweq8ee2j35tq6r5m687kctq9huskt50edv

 

See figure 1 for an example of a Cuba ransomware note.

Figure 1: Sample Cuba Ransom Note 2, as of late August 2022

Greetings! Unfortunately we have to report that your company were

compromised. All your files were

encrypted and you can’t restore them without our private key. Trying

to restore it without our help may

cause complete loss of your data. Also we researched whole your

corporate network and downloaded all

your sensitive data to our servers. If we will not get any contact

from you in the next 3 days we will public

it in our news site.

You can find it there (

https[:]// cuba4ikm4jakjgmkeztyawtdgr2xymvy6nvgw5cglswg3si76icnqd.onion/ )

Tor Browser is needed ( https[:]//www.torproject.org/download/ )

Also we respect your work and time and we are open for communication.

In that case we are ready to discuss

recovering your files and work. We can grant absolute privacy and

compliance with agreements by our side.

Also we can provide all necessary evidence to confirm performance of

our products and statements.

Feel free to contact us with quTox ( https[:]//tox.chat/download.html )

 

Our ToxID: 37790E2D198DFD20C9D2887D4EF7C3E295188842480192689864DCCA3C8BD808A18956768271

 

Alternative method is email: inbox@mail.supports24[.]net

 

Mark your messages with your personal ID:

 

 

Additional resources to detect possible exploitation or compromise:

MITRE ATT&CK TECHNIQUES

Cuba ransomware actors use the ATT&CK techniques listed in Table 6. Note: For details on TTPs listed in the table, see FBI Flash Indicators of Compromise Associated with Cuba Ransomware.

Resource Development

Technique Title

ID

Use

Compromise Infrastructure: Domains

T1584.001

Cuba ransomware actors use compromised networks to conduct their operations.

Initial Access

Technique Title

ID

Use

Valid Accounts

T1078

Cuba ransomware actors have been known to use compromised credentials to get into a victim’s network.

External Remote Services

T1133

Cuba ransomware actors may leverage external-facing remote services to gain initial access to a victim’s network.

Exploit Public-Facing Application

T1190

Cuba ransomware actors are known to exploit vulnerabilities in public-facing systems.

Phishing

T1566

Cuba ransomware actors have sent phishing emails to obtain initial access to systems.

Execution

Technique Title

ID

Use

Command and Scripting Interpreter: PowerShell

T1059.001

Cuba ransomware actors have used PowerShell to escalate privileges.

Software Deployment Tools

T1072

Cuba ransomware actors use Hancitor as a tool to spread malicious files throughout a victim’s network.

Privilege Escalation

Technique Title

ID

Use

Exploitation for Privilege Escalation

T1068

Cuba ransomware actors have exploited ZeroLogon to gain administrator privileges.[2]

Defense Evasion

Technique Title

ID

Use

Impair Defenses: Disable or Modify Tools

T1562.001

Cuba ransomware actors leveraged a loader that disables security tools within the victim network.

Lateral Movement

Technique Title

ID

Use

Remote Services Session: RDP Hijacking

T1563.002

Cuba ransomware actors used RDP sessions to move laterally.

Credential Access

Technique Title

ID

Use

Credential Dumping: LSASS Memory

T1003.001

Cuba ransomware actors use LSASS memory to retrieve stored compromised credentials.

Steal or Forge Kerberos Tickets: Kerberoasting

T1558.003

Cuba ransomware actors used the Kerberoasting technique to identify service accounts linked to active directory.[2]

Command and Control

Technique Title

ID

Use

Proxy: Manipulate Command and Control Communications

T1090

Industrial Spy ransomware actors use HTTP/HTTPS proxy via a C2 server to direct traffic to avoid direct connection. [2]

Mitigations

FBI and CISA recommend network defenders apply the following mitigations to limit potential adversarial use of common system and network discovery techniques and to reduce the risk of compromise by Cuba ransomware:

  • Implement a recovery plan to maintain and retain multiple copies of sensitive or proprietary data and servers in a physically separate, segmented, and secure location (i.e., hard drive, storage device, the cloud).
  • Require all accounts with password logins (e.g., service account, admin accounts, and domain admin accounts) to comply with National Institute for Standards and Technology (NIST) standards for developing and managing password policies.
    • Use longer passwords consisting of at least 8 characters and no more than 64 characters in length.
    • Store passwords in hashed format using industry-recognized password managers.
    • Add password user “salts” to shared login credentials.
    • Avoid reusing passwords.
    • Implement multiple failed login attempt account lockouts.
    • Disable password “hints.”
    • Refrain from requiring password changes more frequently than once per year.
    • Note: NIST guidance suggests favoring longer passwords instead of requiring regular and frequent password resets. Frequent password resets are more likely to result in users developing password “patterns” cyber criminals can easily decipher.
    • Require administrator credentials to install software.
  • Require multifactor authentication for all services to the extent possible, particularly for webmail, virtual private networks, and accounts that access critical systems.
  • Keep all operating systems, software, and firmware up to date. Timely patching is one of the most efficient and cost-effective steps an organization can take to minimize its exposure to cybersecurity threats. Prioritize patching SonicWall firewall vulnerabilities and known exploited vulnerabilities in internet-facing systems. Note: SonicWall maintains a vulnerability list that includes Advisory ID, CVE, and mitigation. Their list can be found at psirt.global.sonicwall.com/vuln-list.
  • Segment networks to prevent the spread of ransomware. Network segmentation can help prevent the spread of ransomware by controlling traffic flows between—and access to—various subnetworks and by restricting adversary lateral movement.
  • Identify, detect, and investigate abnormal activity and potential traversal of the indicated ransomware with a networking monitoring tool. To aid in detecting the ransomware, implement a tool that logs and reports all network traffic, including lateral movement activity on a network. Endpoint detection and response (EDR) tools are particularly useful for detecting lateral connections as they have insight into common and uncommon network connections for each host.
  • Install, regularly update, and enable real time detection for antivirus software on all hosts.
  • Review domain controllers, servers, workstations, and active directories for new and/or unrecognized accounts.
  • Audit user accounts with administrative privileges and configure access controls according to the principle of least privilege.
  • Disable unused ports.
  • Consider adding an email banner to emails received from outside your organization.
  • Disable hyperlinks in received emails.
  • Implement time-based access for accounts set at the admin level and higher. For example, the Just-in-Time (JIT) access method provisions privileged access when needed and can support enforcement of the principle of least privilege (as well as the Zero Trust model). JIT sets a network-wide policy in place to automatically disable admin accounts at the Active Directory level when the account is not in direct need. Individual users may submit their requests through an automated process that grants them access to a specified system for a set timeframe when they need to support the completion of a certain task.
  • Disable command-line and scripting activities and permissions. Privilege escalation and lateral movement often depend on software utilities running from the command line. If threat actors are not able to run these tools, they will have difficulty escalating privileges and/or moving laterally.
  • Maintain offline backups of data, and regularly maintain backup and restoration. By instituting this practice, the organization ensures they will not be severely interrupted, and/or only have irretrievable data.
  • Ensure all backup data is encrypted, immutable (i.e., cannot be altered or deleted), and covers the entire organization’s data infrastructure.
RESOURCES REPORTING

FBI is seeking any information that can be shared, to include boundary logs showing communication to and from foreign IP addresses, a sample ransom note, communications with ransomware actors, Bitcoin wallet information, decryptor files, and/or a benign sample of an encrypted file.

FBI and CISA do not encourage paying ransom as payment does not guarantee victim files will be recovered. Furthermore, payment may also embolden adversaries to target additional organizations, encourage other criminal actors to engage in the distribution of ransomware, and/or fund illicit activities. Regardless of whether you or your organization have decided to pay the ransom, FBI and CISA urge you to promptly report ransomware incidents immediately. Report to a local FBI Field Office, or CISA at us-cert.cisa.gov/report.

DISCLAIMER

The information in this report is being provided “as is” for informational purposes only. FBI and CISA do not endorse any commercial product or service, including any subjects of analysis. Any reference to specific commercial products, processes, or services by service mark, trademark, manufacturer, or otherwise, does not constitute or imply endorsement, recommendation, or favoring by FBI or CISA.

ACKNOWLEDGEMENTS

FBI and CISA would like to thank BlackBerry, ESET, The National Cyber-Forensics and Training Alliance (NCFTA), Palo Alto Networks, and PRODAFT for their contributions to this CSA.

References Revisions
  • December 1, 2022: Initial Version
  • December 12, 2022: Added new IP addresses and IOCs

This product is provided subject to this Notification and this Privacy & Use policy.

Categories: Security Alerts

AA22-321A: #StopRansomware: Hive Ransomware

US-CERT Security Alerts - Thu, 11/17/2022 - 09:00
Original release date: November 17, 2022 | Last revised: November 25, 2022
Summary

Actions to Take Today to Mitigate Cyber Threats from Ransomware:

• Prioritize remediating known exploited vulnerabilities.
• Enable and enforce multifactor authentication with strong passwords
• Close unused ports and remove any application not deemed necessary for day-to-day operations.

Note: This joint Cybersecurity Advisory (CSA) is part of an ongoing #StopRansomware effort to publish advisories for network defenders that detail various ransomware variants and ransomware threat actors. These #StopRansomware advisories include recently and historically observed tactics, techniques, and procedures (TTPs) and indicators of compromise (IOCs) to help organizations protect against ransomware. Visit stopransomware.gov to see all #StopRansomware advisories and to learn more about other ransomware threats and no-cost resources.

The Federal Bureau of Investigation (FBI), the Cybersecurity and Infrastructure Security Agency (CISA), and the Department of Health and Human Services (HHS) are releasing this joint CSA to disseminate known Hive IOCs and TTPs identified through FBI investigations as recently as November 2022.

FBI, CISA, and HHS encourage organizations to implement the recommendations in the Mitigations section of this CSA to reduce the likelihood and impact of ransomware incidents. Victims of ransomware operations should report the incident to their local FBI field office or CISA.

Download the PDF version of this report: pdf, 852.9 kb.

For a downloadable copy of IOCs, see AA22-321A.stix (STIX, 43.6 kb).

Technical Details

Note: This advisory uses the MITRE ATT&CK® for Enterprise framework, version 12. See MITRE ATT&CK for Enterprise for all referenced tactics and techniques.

As of November 2022, Hive ransomware actors have victimized over 1,300 companies worldwide, receiving approximately US$100 million in ransom payments, according to FBI information. Hive ransomware follows the ransomware-as-a-service (RaaS) model in which developers create, maintain, and update the malware, and affiliates conduct the ransomware attacks. From June 2021 through at least November 2022, threat actors have used Hive ransomware to target a wide range of businesses and critical infrastructure sectors, including Government Facilities, Communications, Critical Manufacturing, Information Technology, and especially Healthcare and Public Health (HPH).

The method of initial intrusion will depend on which affiliate targets the network. Hive actors have gained initial access to victim networks by using single factor logins via Remote Desktop Protocol (RDP), virtual private networks (VPNs), and other remote network connection protocols [T1133]. In some cases, Hive actors have bypassed multifactor authentication (MFA) and gained access to FortiOS servers by exploiting Common Vulnerabilities and Exposures (CVE) CVE-2020-12812. This vulnerability enables a malicious cyber actor to log in without a prompt for the user’s second authentication factor (FortiToken) when the actor changes the case of the username.

Hive actors have also gained initial access to victim networks by distributing phishing emails with malicious attachments [T1566.001] and by exploiting the following vulnerabilities against Microsoft Exchange servers [T1190]:

  • CVE-2021-31207 - Microsoft Exchange Server Security Feature Bypass Vulnerability
  • CVE-2021-34473 - Microsoft Exchange Server Remote Code Execution Vulnerability
  • CVE-2021-34523 - Microsoft Exchange Server Privilege Escalation Vulnerability

After gaining access, Hive ransomware attempts to evade detention by executing processes to:

  • Identify processes related to backups, antivirus/anti-spyware, and file copying and then terminating those processes to facilitate file encryption [T1562].
  • Stop the volume shadow copy services and remove all existing shadow copies via vssadmin on command line or via PowerShell [T1059] [T1490].
  • Delete Windows event logs, specifically the System, Security and Application logs [T1070].

Prior to encryption, Hive ransomware removes virus definitions and disables all portions of Windows Defender and other common antivirus programs in the system registry [T1112].

Hive actors exfiltrate data likely using a combination of Rclone and the cloud storage service Mega.nz [T1537]. In addition to its capabilities against the Microsoft Windows operating system, Hive ransomware has known variants for Linux, VMware ESXi, and FreeBSD.

During the encryption process, a file named *.key (previously *.key.*) is created in the root directory (C:\ or /root/). Required for decryption, this key file only exists on the machine where it was created and cannot be reproduced. The ransom note, HOW_TO_DECRYPT.txt is dropped into each affected directory and states the *.key file cannot be modified, renamed, or deleted, otherwise the encrypted files cannot be recovered [T1486]. The ransom note contains a “sales department” .onion link accessible through a TOR browser, enabling victim organizations to contact the actors through a live chat panel to discuss payment for their files. However, some victims reported receiving phone calls or emails from Hive actors directly to discuss payment.

The ransom note also threatens victims that a public disclosure or leak site accessible on the TOR site, “HiveLeaks”, contains data exfiltrated from victim organizations who do not pay the ransom demand (see figure 1 below). Additionally, Hive actors have used anonymous file sharing sites to disclose exfiltrated data (see table 1 below).

 

Table 1: Anonymous File Sharing Sites Used to Disclose Data

https://anonfiles[.]com

https://mega[.]nz

https://send.exploit[.]in

https://ufile[.]io

https://www.sendspace[.]com

https://privatlab[.]net

https://privatlab[.]com

 

Once the victim organization contacts Hive actors on the live chat panel, Hive actors communicate the ransom amount and the payment deadline. Hive actors negotiate ransom demands in U.S. dollars, with initial amounts ranging from several thousand to millions of dollars. Hive actors demand payment in Bitcoin.

Hive actors have been known to reinfect—with either Hive ransomware or another ransomware variant—the networks of victim organizations who have restored their network without making a ransom payment.

Indicators of Compromise

Threat actors have leveraged the following IOCs during Hive ransomware compromises. Note: Some of these indicators are legitimate applications that Hive threat actors used to aid in further malicious exploitation. FBI, CISA, and HHS recommend removing any application not deemed necessary for day-to-day operations. See tables 2–3 below for IOCs obtained from FBI threat response investigations as recently as November 2022.

Table 2: Known IOCs as of November 2022

Known IOCs - Files

HOW_TO_DECRYPT.txt typically in directories with encrypted files

*.key typically in the root directory, i.e., C:\ or /root

hive.bat

shadow.bat

asq.r77vh0[.]pw - Server hosted malicious HTA file

asq.d6shiiwz[.]pw - Server referenced in malicious regsvr32 execution

asq.swhw71un[.]pw - Server hosted malicious HTA file

asd.s7610rir[.]pw - Server hosted malicious HTA file

Windows_x64_encrypt.dll

Windows_x64_encrypt.exe

Windows_x32_encrypt.dll

Windows_x32_encrypt.exe

Linux_encrypt

Esxi_encrypt

Known IOCs – Events

System, Security and Application Windows event logs wiped

Microsoft Windows Defender AntiSpyware Protection disabled

Microsoft Windows Defender AntiVirus Protection disabled

Volume shadow copies deleted

Normal boot process prevented

Known IOCs – Logged Processes

wevtutil.exe cl system

wevtutil.exe cl security

wevtutil.exe cl application

vssadmin.exe delete shadows /all /quiet

wmic.exe SHADOWCOPY /nointeractive

wmic.exe shadowcopy delete

bcdedit.exe /set {default} bootstatuspolicy ignoreallfailures

bcdedit.exe /set {default} recoveryenabled no

 

Table 3: Potential IOC IP Addresses as of November 2022 Note: Some of these observed IP addresses are more than a year old. FBI and CISA recommend vetting or investigating these IP addresses prior to taking forward-looking action like blocking.

Potential IOC IP Addresses for Compromise or Exfil:

84.32.188[.]57

84.32.188[.]238

93.115.26[.]251

185.8.105[.]67

181.231.81[.]239

185.8.105[.]112

186.111.136[.]37

192.53.123[.]202

158.69.36[.]149

46.166.161[.]123

108.62.118[.]190

46.166.161[.]93

185.247.71[.]106

46.166.162[.]125

5.61.37[.]207

46.166.162[.]96

185.8.105[.]103

46.166.169[.]34

5.199.162[.]220

93.115.25[.]139

5.199.162[.]229

93.115.27[.]148

89.147.109[.]208

83.97.20[.]81

5.61.37[.]207

5.199.162[.]220

5.199.162[.]229;

46.166.161[.]93

46.166.161[.]123;

46.166.162[.]96

46.166.162[.]125

46.166.169[.]34

83.97.20[.]81

84.32.188[.]238

84.32.188[.]57

89.147.109[.]208

93.115.25[.]139;

93.115.26[.]251

93.115.27[.]148

108.62.118[.]190

158.69.36[.]149/span>

181.231.81[.]239

185.8.105[.]67

185.8.105[.]103

185.8.105[.]112

185.247.71[.]106

186.111.136[.]37

192.53.123[.]202

 

MITRE ATT&CK TECHNIQUES

See table 4 for all referenced threat actor tactics and techniques listed in this advisory.

Table 4: Hive Actors ATT&CK Techniques for Enterprise

Initial Access

Technique Title

ID

Use

External Remote Services

T1133

Hive actors gain access to victim networks by using single factor logins via RDP, VPN, and other remote network connection protocols.

Exploit Public-Facing Application

T1190

Hive actors gain access to victim network by exploiting the following Microsoft Exchange vulnerabilities: CVE-2021-34473, CVE-2021-34523, CVE-2021-31207, CVE-2021-42321.

Phishing

T1566.001

Hive actors gain access to victim networks by distributing phishing emails with malicious attachments.

Execution

Technique Title

ID

Use

Command and Scripting Interpreter

T1059

Hive actors looks to stop the volume shadow copy services and remove all existing shadow copies via vssadmin on command line or PowerShell.

Defense Evasion

Technique Title

ID

Use

Indicator Removal on Host

T1070

Hive actors delete Windows event logs, specifically, the System, Security and Application logs.

Modify Registry

T1112

Hive actors set registry values for DisableAntiSpyware and DisableAntiVirus to 1.

Impair Defenses

T1562

Hive actors seek processes related to backups, antivirus/anti-spyware, and file copying and terminates those processes to facilitate file encryption.

Exfiltration

Technique Title

ID

Use

Transfer Data to Cloud Account

T1537

Hive actors exfiltrate data from victims, using a possible combination of Rclone and the cloud storage service Mega.nz.

Impact

Technique Title

 

Use

Data Encrypted for Impact

T1486

Hive actors deploy a ransom note HOW_TO_DECRYPT.txt into each affected directory which states the *.key file cannot be modified, renamed, or deleted, otherwise the encrypted files cannot be recovered.

Inhibit System Recovery

T1490

Hive actors looks to stop the volume shadow copy services and remove all existing shadow copies via vssadmin via command line or PowerShell.

Mitigations

FBI, CISA, and HHS recommend organizations, particularly in the HPH sector, implement the following to limit potential adversarial use of common system and network discovery techniques and to reduce the risk of compromise by Hive ransomware:

  • Verify Hive actors no longer have access to the network.
  • Install updates for operating systems, software, and firmware as soon as they are released. Prioritize patching VPN servers, remote access software, virtual machine software, and known exploited vulnerabilities. Consider leveraging a centralized patch management system to automate and expedite the process.
  • Require phishing-resistant MFA for as many services as possible—particularly for webmail, VPNs, accounts that access critical systems, and privileged accounts that manage backups.
  • If used, secure and monitor RDP.
    • Limit access to resources over internal networks, especially by restricting RDP and using virtual desktop infrastructure.
    • After assessing risks, if you deem RDP operationally necessary, restrict the originating sources and require MFA to mitigate credential theft and reuse.
    • If RDP must be available externally, use a VPN, virtual desktop infrastructure, or other means to authenticate and secure the connection before allowing RDP to connect to internal devices.
    • Monitor remote access/RDP logs, enforce account lockouts after a specified number of attempts to block brute force campaigns, log RDP login attempts, and disable unused remote access/RDP ports.
    • Be sure to properly configure devices and enable security features.
    • Disable ports and protocols not used for business purposes, such as RDP Port 3389/TCP.
  • Maintain offline backups of data, and regularly maintain backup and restoration. By instituting this practice, the organization ensures they will not be severely interrupted, and/or only have irretrievable data.
  • Ensure all backup data is encrypted, immutable (i.e., cannot be altered or deleted), and covers the entire organization’s data infrastructure. Ensure your backup data is not already infected.,
  • Monitor cyber threat reporting regarding the publication of compromised VPN login credentials and change passwords/settings if applicable.
  • Install and regularly update anti-virus or anti-malware software on all hosts.
  • Enable PowerShell Logging including module logging, script block logging and transcription.
  • Install an enhanced monitoring tool such as Sysmon from Microsoft for increased logging.
  • Review the following additional resources.
    • The joint advisory from Australia, Canada, New Zealand, the United Kingdom, and the United States on Technical Approaches to Uncovering and Remediating Malicious Activity provides additional guidance when hunting or investigating a network and common mistakes to avoid in incident handling.
    • The Cybersecurity and Infrastructure Security Agency-Multi-State Information Sharing & Analysis Center Joint Ransomware Guide covers additional best practices and ways to prevent, protect, and respond to a ransomware attack.
    • StopRansomware.gov is the U.S. Government’s official one-stop location for resources to tackle ransomware more effectively.

If your organization is impacted by a ransomware incident, FBI, CISA, and HHS recommend the following actions.

  • Isolate the infected system. Remove the infected system from all networks, and disable the computer’s wireless, Bluetooth, and any other potential networking capabilities. Ensure all shared and networked drives are disconnected.
  • Turn off other computers and devices. Power-off and segregate (i.e., remove from the network) the infected computer(s). Power-off and segregate any other computers or devices that share a network with the infected computer(s) that have not been fully encrypted by ransomware. If possible, collect and secure all infected and potentially infected computers and devices in a central location, making sure to clearly label any computers that have been encrypted. Powering-off and segregating infected computers and computers that have not been fully encrypted may allow for the recovery of partially encrypted files by specialists.
  • Secure your backups. Ensure that your backup data is offline and secure. If possible, scan your backup data with an antivirus program to check that it is free of malware.

In addition, FBI, CISA, and HHS urge all organizations to apply the following recommendations to prepare for, mitigate/prevent, and respond to ransomware incidents.

Preparing for Cyber Incidents
  • Review the security posture of third-party vendors and those interconnected with your organization. Ensure all connections between third-party vendors and outside software or hardware are monitored and reviewed for suspicious activity.
  • Implement listing policies for applications and remote access that only allow systems to execute known and permitted programs under an established security policy.
  • Document and monitor external remote connections. Organizations should document approved solutions for remote management and maintenance, and immediately investigate if an unapproved solution is installed on a workstation.
  • Implement a recovery plan to maintain and retain multiple copies of sensitive or proprietary data and servers in a physically separate, segmented, and secure location (i.e., hard drive, storage device, the cloud).
Identity and Access Management
  • Require all accounts with password logins (e.g., service account, admin accounts, and domain admin accounts) to comply with National Institute of Standards and Technology (NIST) standards for developing and managing password policies.
    • Use longer passwords consisting of at least 8 characters and no more than 64 characters in length.
    • Store passwords in hashed format using industry-recognized password managers.
    • Add password user “salts” to shared login credentials.
    • Avoid reusing passwords.
    • Implement multiple failed login attempt account lockouts.
    • Disable password “hints.”
    • Refrain from requiring password changes more frequently than once per year unless a password is known or suspected to be compromised.
      Note: NIST guidance suggests favoring longer passwords instead of requiring regular and frequent password resets. Frequent password resets are more likely to result in users developing password “patterns” cyber criminals can easily decipher.
    • Require administrator credentials to install software.
  • Require phishing-resistant multifactor authentication for all services to the extent possible, particularly for webmail, virtual private networks, and accounts that access critical systems.
  • Review domain controllers, servers, workstations, and active directories for new and/or unrecognized accounts.
  • Audit user accounts with administrative privileges and configure access controls according to the principle of least privilege.
  • Implement time-based access for accounts set at the admin level and higher. For example, the Just-in-Time (JIT) access method provisions privileged access when needed and can support enforcement of the principle of least privilege (as well as the Zero Trust model). This is a process where a network-wide policy is set in place to automatically disable admin accounts at the Active Directory level when the account is not in direct need. Individual users may submit their requests through an automated process that grants them access to a specified system for a set timeframe when they need to support the completion of a certain task. 
Protective Controls and Architecture
  • Segment networks to prevent the spread of ransomware. Network segmentation can help prevent the spread of ransomware by controlling traffic flows between—and access to—various subnetworks and by restricting adversary lateral movement.
  • Identify, detect, and investigate abnormal activity and potential traversal of the indicated ransomware with a networking monitoring tool. To aid in detecting the ransomware, implement a tool that logs and reports all network traffic, including lateral movement activity on a network. Endpoint detection and response (EDR) tools are particularly useful for detecting lateral connections as they have insight into common and uncommon network connections for each host.
  • Install, regularly update, and enable real time detection for antivirus software on all hosts.

Vulnerability and Configuration Management

  • Consider adding an email banner to emails received from outside your organization.
  • Disable command-line and scripting activities and permissions. Privilege escalation and lateral movement often depend on software utilities running from the command line. If threat actors are not able to run these tools, they will have difficulty escalating privileges and/or moving laterally.
  • Ensure devices are properly configured and that security features are enabled
  • Restrict Server Message Block (SMB) Protocol within the network to only access necessary servers and remove or disable outdated versions of SMB (i.e., SMB version 1). Threat actors use SMB to propagate malware across organizations.
REFERENCES INFORMATION REQUESTED

The FBI, CISA, and HHS do not encourage paying a ransom to criminal actors. Paying a ransom may embolden adversaries to target additional organizations, encourage other criminal actors to engage in the distribution of ransomware, and/or fund illicit activities. Paying the ransom also does not guarantee that a victim’s files will be recovered. However, the FBI, CISA, and HHS understand that when businesses are faced with an inability to function, executives will evaluate all options to protect their shareholders, employees, and customers. Regardless of whether you or your organization decide to pay the ransom, the FBI, CISA, and HHS urge you to promptly report ransomware incidents to your local FBI field office, or to CISA at report@cisa.gov or (888) 282-0870. Doing so provides investigators with the critical information they need to track ransomware attackers, hold them accountable under US law, and prevent future attacks. 

The FBI may seek the following information that you determine you can legally share, including:

  • Recovered executable files
  • Live random access memory (RAM) capture
  • Images of infected systems
  • Malware samples
  • IP addresses identified as malicious or suspicious
  • Email addresses of the attackers
  • A copy of the ransom note
  • Ransom amount
  • Bitcoin wallets used by the attackers
  • Bitcoin wallets used to pay the ransom
  • Post-incident forensic reports
DISCLAIMER

The information in this report is being provided “as is” for informational purposes only. FBI, CISA, and HHS do not endorse any commercial product or service, including any subjects of analysis. Any reference to specific commercial products, processes, or services by service mark, trademark, manufacturer, or otherwise, does not constitute or imply endorsement, recommendation, or favoring by FBI, CISA, or HHS.

 

Revisions
  • Initial Version: November 17, 2022

This product is provided subject to this Notification and this Privacy & Use policy.

Categories: Security Alerts

AA22-320A: Iranian Government-Sponsored APT Actors Compromise Federal Network, Deploy Crypto Miner, Credential Harvester

US-CERT Security Alerts - Wed, 11/16/2022 - 07:04
Original release date: November 16, 2022 | Last revised: November 25, 2022
Summary

From mid-June through mid-July 2022, CISA conducted an incident response engagement at a Federal Civilian Executive Branch (FCEB) organization where CISA observed suspected advanced persistent threat (APT) activity. In the course of incident response activities, CISA determined that cyber threat actors exploited the Log4Shell vulnerability in an unpatched VMware Horizon server, installed XMRig crypto mining software, moved laterally to the domain controller (DC), compromised credentials, and then implanted Ngrok reverse proxies on several hosts to maintain persistence. CISA and the Federal Bureau of Investigation (FBI) assess that the FCEB network was compromised by Iranian government-sponsored APT actors.

CISA and FBI are releasing this Cybersecurity Advisory (CSA) providing the suspected Iranian government-sponsored actors’ tactics, techniques, and procedures (TTPs) and indicators of compromise (IOCs) to help network defenders detect and protect against related compromises.

CISA and FBI encourage all organizations with affected VMware systems that did not immediately apply available patches or workarounds to assume compromise and initiate threat hunting activities. If suspected initial access or compromise is detected based on IOCs or TTPs described in this CSA, CISA and FBI encourage organizations to assume lateral movement by threat actors, investigate connected systems (including the DC), and audit privileged accounts. All organizations, regardless of identified evidence of compromise, should apply the recommendations in the Mitigations section of this CSA to protect against similar malicious cyber activity.

For more information on Iranian government-sponsored Iranian malicious cyber activity, see CISA’s Iran Cyber Threat Overview and Advisories webpage and FBI’s Iran Threats webpage.

Download the PDF version of this report: pdf, 528 kb.

For a downloadable copy of the Malware Analysis Report (MAR) accompanying this report, see: MAR 10387061-1.v1.

For a downloadable copy of IOCs, see: AA22-320A.stix, 1.55 mb.

Technical Details

Note: This advisory uses the MITRE ATT&CK for Enterprise framework, version 11. See the MITRE ATT&CK Tactics and Techniques section for a table of the threat actors’ activity mapped to MITRE ATT&CK® tactics and techniques with corresponding mitigation and/or detection recommendations.

Overview

In April 2022, CISA conducted retrospective analysis using EINSTEIN—an FCEB-wide intrusion detection system (IDS) operated and monitored by CISA—and identified suspected APT activity on an FCEB organization’s network. CISA observed bi-directional traffic between the network and a known malicious IP address associated with exploitation of the Log4Shell vulnerability (CVE-2021-44228) in VMware Horizon servers. In coordination with the FCEB organization, CISA initiated threat hunting incident response activities; however, prior to deploying an incident response team, CISA observed additional suspected APT activity. Specifically, CISA observed HTTPS activity from IP address 51.89.181[.]64 to the organization’s VMware server. Based on trusted third-party reporting, 51.89.181[.]64 is a Lightweight Directory Access Protocol (LDAP) server associated with threat actors exploiting Log4Shell. Following HTTPS activity, CISA observed a suspected LDAP callback on port 443 to this IP address. CISA also observed a DNS query for us‐nation‐ny[.]cf that resolved back to 51.89.181[.]64 when the victim server was returning this Log4Shell LDAP callback to the actors’ server.

CISA assessed that this traffic indicated a confirmed compromise based on the successful callback to the indicator and informed the organization of these findings; the organization investigated the activity and found signs of compromise. As trusted-third party reporting associated Log4Shell activity from 51.89.181[.]64 with lateral movement and targeting of DCs, CISA suspected the threat actors had moved laterally and compromised the organization’s DC.

From mid-June through mid-July 2022, CISA conducted an onsite incident response engagement and determined that the organization was compromised as early as February 2022, by likely Iranian government-sponsored APT actors who installed XMRig crypto mining software. The threat actors also moved laterally to the domain controller, compromised credentials, and implanted Ngrok reverse proxies.

Threat Actor Activity

In February 2022, the threat actors exploited Log4Shell [T1190] for initial access [TA0001] to the organization’s unpatched VMware Horizon server. As part of their initial exploitation, CISA observed a connection to known malicious IP address 182.54.217[.]2 lasting 17.6 seconds.

The actors’ exploit payload ran the following PowerShell command [T1059.001] that added an exclusion rule to Windows Defender [T1562.001]:

powershell try{Add-MpPreference -ExclusionPath 'C:\'; Write-Host 'added-exclusion'} catch {Write-Host 'adding-exclusion-failed' }; powershell -enc "$BASE64 encoded payload to download next stage and execute it"

The exclusion rule allowlisted the entire c:\drive, enabling threat actors to download tools to the c:\drive without virus scans. The exploit payload then downloaded mdeploy.text from 182.54.217[.]2/mdepoy.txt to C:\users\public\mde.ps1 [T1105]. When executed, mde.ps1 downloaded file.zip from 182.54.217[.]2 and removed mde.ps1 from the disk [T1070.004].

file.zip contained XMRig cryptocurrency mining software and associated configuration files.

  • WinRing0x64.sys – XMRig Miner driver
  • wuacltservice.exe – XMRig Miner
  • config.json – XMRig miner configuration
  • RuntimeBroker.exe – Associated file. This file can create a local user account [T1136.001] and tests for internet connectivity by pinging 8.8.8.8 [T1016.001]. The exploit payload created a Scheduled Task [T1053.005] that executed RuntimeBroker.exe daily as SYSTEM. Note: By exploiting Log4Shell, the actors gained access to a VMware service account with administrator and system level access. The Scheduled Task was named RuntimeBrokerService.exe to masquerade as a legitimate Windows task.

See MAR 10387061-1.v1 for additional information, including IOCs, on these four files.

After obtaining initial access and installing XMRig on the VMWare Horizon server, the actors used RDP [T1021.001] and the built-in Windows user account DefaultAccount [T1078.001] to move laterally [TA0008] to a VMware VDI-KMS host. Once the threat actor established themselves on the VDI-KMS host, CISA observed the actors download around 30 megabytes of files from transfer[.]sh server associated with 144.76.136[.]153. The actors downloaded the following tools:

  • PsExec – a Microsoft signed tool for system administrators.
  • Mimikatz – a credential theft tool.
  • Ngrok – a reverse proxy tool for proxying an internal service out onto an Ngrok domain, which the user can then access at a randomly generated subdomain at *.ngrok[.]io. CISA has observed this tool in use by some commercial products for benign purposes; however, this process bypasses typical firewall controls and may be a potentially unwanted application in production environments. Ngrok is known to be used for malicious purposes.[1]

The threat actors then executed Mimikatz on VDI-KMS to harvest credentials and created a rogue domain administrator account [T1136.002]. Using the newly created account, the actors leveraged RDP to propagate to several hosts within the network. Upon logging into each host, the actors manually disabled Windows Defender via the Graphical User Interface (GUI) and implanted Ngrok executables and configuration files. The threat actors were able to implant Ngrok on multiple hosts to ensure Ngrok’s persistence should they lose access to a machine during a routine reboot. The actors were able to proxy [T1090] RDP sessions, which were only observable on the local network as outgoing HTTPS port 443 connections to tunnel.us.ngrok[.]com and korgn.su.lennut[.]com (the prior domain in reverse). It is possible, but was not observed, that the threat actors configured a custom domain, or used other Ngrok tunnel domains, wildcarded here as *.ngrok[.]com, *.ngrok[.]io, ngrok.*.tunnel[.]com, or korgn.*.lennut[.]com.

Once the threat actors established a deep foothold in the network and moved laterally to the domain controller, they executed the following PowerShell command on the Active Directory to obtain a list of all machines attached to the domain [T1018]:

Powershell.exe get-adcomputer -filter * -properties * | select name,operatingsystem,ipv4address >

The threat actors also changed the password for the local administrator account [T1098] on several hosts as a backup should the rogue domain administrator account get detected and terminated. Additionally, the threat actor was observed attempting to dump the Local Security Authority Subsystem Service (LSASS) process [T1003.001] with task manager but this was stopped by additional anti-virus the FCEB organization had installed.

MITRE ATT&CK TACTICS AND TECHNIQUES

See table 1 for all referenced threat actor tactics and techniques in this advisory, as well as corresponding detection and/or mitigation recommendations. For additional mitigations, see the Mitigations section.

Table 1: Cyber Threat Actors ATT&CK Techniques for Enterprise

Initial Access

Technique Title

ID

Use

Recommendations

Exploit Public-Facing Application

T1190

The actors exploited Log4Shell for initial access to the organization’s VMware Horizon server.

Mitigation/Detection: Use a firewall or web-application firewall and enable logging to prevent and detect potential Log4Shell exploitation attempts [M1050].

Mitigation: Perform regular vulnerability scanning to detect Log4J vulnerabilities and update Log4J software using vendor provided patches [M1016],[M1051].

Execution

Technique Title

ID

Use

Recommendation

Command and Scripting Interpreter: PowerShell

T1059.001

The actors ran PowerShell commands that added an exclusion rule to Windows Defender.

The actors executed PowerShell on the AD to obtain a list of machines on the domain.

Mitigation: Disable or remove PowerShell for non-administrative users [M1042],[M1026] or enable code-signing to execute only signed scripts [M1045].

Mitigation: Employ anti-malware to automatically detect and quarantine malicious scripts [M1049].

Persistence

Technique Title

ID

Use

Recommendations

Account Manipulation

T1098

The actors changed the password for the local administrator account on several hosts.

Mitigation: Use multifactor authentication for user and privileged accounts [M1032].

Detection: Monitor events for changes to account objects and/or permissions on systems and the domain, such as event IDs 4738, 4728, and 4670. Monitor for modification of accounts in correlation with other suspicious activity [DS0002].

Create Account: Local Account

T1136.001

The actors’ malware can create local user accounts.

Mitigation: Configure access controls and firewalls to limit access to domain controllers and systems used to create and manage accounts.

Detection: Monitor executed commands and arguments for actions that are associated with local account creation, such as net user /add , useradd, and dscl -create [DS0017].

Detection: Enable logging for new user creation [DS0002].

Create Account: Domain Account

T1136.002

The actors used Mimikatz to create a rogue domain administrator account.

Mitigation: Configure access controls and firewalls to limit access to domain controllers and systems used to create and manage accounts.

Detection: Enable logging for new user creation, especially domain administrator accounts [DS0002].

Scheduled Task/Job: Scheduled Task

T1053.005

The actors’ exploit payload created Scheduled Task RuntimeBrokerService.exe, which executed RuntimeBroker.exe daily as SYSTEM.

Mitigation: Configure settings for scheduled tasks to force tasks to run under the context of the authenticated account instead of allowing them to run as SYSTEM [M1028].

Detection: Monitor for newly constructed processes and/or command-lines that execute from the svchost.exe in Windows 10 and the Windows Task Scheduler taskeng.exe for older versions of Windows [DS0009]

Detection: Monitor for newly constructed scheduled jobs by enabling the Microsoft-Windows-TaskScheduler/Operational setting within the event logging service [DS0003].

Valid Accounts: Default Accounts

T1078.001

The actors used built-in Windows user account DefaultAccount.

Mitigation: Change default usernames and passwords immediately after the installation and before deployment to a production environment [M1027].

Detection: Develop rules to monitor logon behavior across default accounts that have been activated or logged into [DS0028].

Defense Evasion

Technique Title

ID

Use

Recommendations

Impair Defenses: Disable or Modify Tools

           

T1562.001

The actors added an exclusion rule to Windows Defender. The tool allowlisted the entire c:\drive, enabling the actors to bypass virus scans for tools they downloaded to the c:\drive.

The actors manually disabled Windows Defender via the GUI.

Mitigation: Ensure proper user permissions are in place to prevent adversaries from disabling or interfering with security services. [M1018].

Detection: Monitor for changes made to Windows Registry keys and/or values related to services and startup programs that correspond to security tools such as HKLM:\SOFTWARE\Policies\Microsoft\Windows Defender [DS0024].

Detection: Monitor for telemetry that provides context for modification or deletion of information related to security software processes or services such as Windows Defender definition files in Windows and System log files in Linux [DS0013].

Detection: Monitor processes for unexpected termination related to security tools/services [DS0009].

Indicator Removal on Host: File Deletion

T1070.004

The actors removed malicious file mde.ps1 from the dis.

Detection: Monitor executed commands and arguments for actions that could be utilized to unlink, rename, or delete files [DS0017].

Detection: Monitor for unexpected deletion of files from the system [DS0022].

Credential Access

Technique Title

ID

Use

Recommendations

OS Credential Dumping: LSASS Memory

T1003.001

The actors were observed trying to dump LSASS process.

Mitigation: With Windows 10, Microsoft implemented new protections called Credential Guard to protect the LSA secrets that can be used to obtain credentials through forms of credential dumping [M1043]

Mitigation: On Windows 10, enable Attack Surface Reduction (ASR) rules to secure LSASS and prevent credential stealing [M1040].

Mitigation: Ensure that local administrator accounts have complex, unique passwords across all systems on the network [M1027].

Detection: Monitor for unexpected processes interacting with LSASS.exe. Common credential dumpers such as Mimikatz access LSASS.exe by opening the process, locating the LSA secrets key, and decrypting the sections in memory where credential details are stored. [DS0009].

Detection: Monitor executed commands and arguments that may attempt to access credential material stored in the process memory of the LSASS [DS0017].

Credentials from Password Stores

T1555

The actors used Mimikatz to harvest credentials.

Mitigation: Organizations may consider weighing the risk of storing credentials in password stores and web browsers. If system, software, or web browser credential disclosure is a significant concern, technical controls, policy, and user training may be used to prevent storage of credentials in improper locations [M1027].

Detection: Monitor for processes being accessed that may search for common password storage locations to obtain user credentials [DS0009].

Detection: Monitor executed commands and arguments that may search for common password storage locations to obtain user credentials [DS0017].

Discovery

Technique Title

ID

Use

Recommendations

Remote System Discovery

T1018

The actors executed a PowerShell command on the AD to obtain a list of all machines attached to the domain.

Detection: Monitor executed commands and arguments that may attempt to get a listing of other systems by IP address, hostname, or other logical identifier on a network that may be used for lateral movement [DS0017].

Detection: Monitor for newly constructed network connections associated with pings/scans that may attempt to get a listing of other systems by IP address, hostname, or other logical identifier on a network that may be used for lateral movement [DS0029].

Detection: Monitor for newly executed processes that can be used to discover remote systems, such as ping.exe and tracert.exe, especially when executed in quick succession [DS0009].

System Network Configuration Discovery: Internet Connection Discovery

T1016.001

The actors’ malware tests for internet connectivity by pinging 8.8.8.8.

Mitigation: Monitor executed commands, arguments [DS0017] and executed processes (e.g., tracert or ping) [DS0009] that may check for internet connectivity on compromised systems.

Lateral Movement

Technique Title

ID

Use

Recommendations

Remote Services: Remote Desktop Protocol

T1021.001

The actors used RDP to move laterally to multiple hosts on the network.

Mitigation: Use MFA for remote logins [M1032].

Mitigation: Disable the RDP service if it is unnecessary [M1042].

Mitigation: Do not leave RDP accessible from the internet. Enable firewall rules to block RDP traffic between network security zones within a network [M1030].

Mitigation: Consider removing the local Administrators group from the list of groups allowed to log in through RDP [M1026].

Detection: Monitor for user accounts logged into systems associated with RDP (ex: Windows EID 4624 Logon Type 10). Other factors, such as access patterns (ex: multiple systems over a relatively short period of time) and activity that occurs after a remote login, may indicate suspicious or malicious behavior with RDP [DS0028].

Command and Control

Technique Title

ID

Use

Recommendations

Proxy

T1090

The actors used Ngrok to proxy RDP connections and to perform command and control.

Mitigation: Traffic to known anonymity networks and C2 infrastructure can be blocked through the use of network allow and block lists [M1037].

Detection: Monitor and analyze traffic patterns and packet inspection associated to protocol(s) that do not follow the expected protocol standards and traffic flows (e.g., extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure) [DS0029].

Ingress Tool Transfer

T1105

The actors downloaded malware and multiple tools to the network, including PsExec, Mimikatz, and Ngrok.

Mitigation: Employ anti-malware to automatically detect and quarantine malicious scripts [M1049].

 

 

INCIDENT RESPONSE

If suspected initial access or compromise is detected based on IOCs or TTPs in this CSA, CISA encourages organizations to assume lateral movement by threat actors and investigate connected systems and the DC.

CISA recommends organizations apply the following steps before applying any mitigations, including patching.

  1. Immediately isolate affected systems.
  2. Collect and review relevant logs, data, and artifacts. Take a memory capture of the device(s) and a forensic image capture for detailed analysis.
  3. Consider soliciting support from a third-party incident response organization that can provide subject matter expertise to ensure the actor is eradicated from the network and to avoid residual issues that could enable follow-on exploitation.
  4. Report incidents to CISA via CISA’s 24/7 Operations Center (report@cisa.gov or 888-282-0870) or your local FBI field office, or FBI’s 24/7 Cyber Watch (CyWatch) at (855) 292-3937 or by e-mail at CyWatch@fbi.gov.
     
Mitigations

CISA and FBI recommend implementing the mitigations below and in Table 1 to improve your organization's cybersecurity posture on the basis of threat actor behaviors.

  • Install updated builds to ensure affected VMware Horizon and UAG systems are updated to the latest version.
    • If updates or workarounds were not promptly applied following VMware’s release of updates for Log4Shell in December 2021, treat those VMware Horizon systems as compromised. Follow the pro-active incident response procedures outlined above prior to applying updates. If no compromise is detected, apply these updates as soon as possible.
      • See VMware Security Advisory VMSA-2021-0028.13 and VMware Knowledge Base (KB) 87073 to determine which VMware Horizon components are vulnerable.
      • Note: Until the update is fully implemented, consider removing vulnerable components from the internet to limit the scope of traffic. While installing the updates, ensure network perimeter access controls are as restrictive as possible.
      • If upgrading is not immediately feasible, see KB87073 and KB87092 for vendor-provided temporary workarounds. Implement temporary solutions using an account with administrative privileges. Note that these temporary solutions should not be treated as permanent fixes; vulnerable components should be upgraded to the latest build as soon as possible.
      • Prior to implementing any temporary solution, ensure appropriate backups have been completed.
      • Verify successful implementation of mitigations by executing the vendor supplied script Horizon_Windows_Log4j_Mitigations.zip without parameters to ensure that no vulnerabilities remain. See KB87073 for details.
  • Keep all software up to date and prioritize patching known exploited vulnerabilities (KEVs).
  • Minimize the internet-facing attack surface by hosting essential services on a segregated DMZ, ensuring strict network perimeter access controls, and not hosting internet-facing services that are not essential to business operations. Where possible, implement regularly updated web application firewalls (WAF) in front of public-facing services. WAFs can protect against web-based exploitation using signatures and heuristics that are likely to block or alert on malicious traffic.
  • Use best practices for identity and access management (IAM) by implementing phishing resistant multifactor authentication (MFA), enforcing use of strong passwords, regularly auditing administrator accounts and permissions, and limiting user access through the principle of least privilege. Disable inactive accounts uniformly across the AD, MFA systems, etc.
    • If using Windows 10 version 1607 or Windows Server 2016 or later, monitor or disable Windows DefaultAccount, also known as the Default System Managed Account (DSMA).
  • Audit domain controllers to log successful Kerberos Ticket Granting Service (TGS) requests and ensure the events are monitored for anomalous activity.  
    • Secure accounts.
    • Enforce the principle of least privilege. Administrator accounts should have the minimum permission necessary to complete their tasks.
    • Ensure there are unique and distinct administrative accounts for each set of administrative tasks.
    • Create non-privileged accounts for privileged users and ensure they use the non-privileged accounts for all non-privileged access (e.g., web browsing, email access).
  • Create a deny list of known compromised credentials and prevent users from using known-compromised passwords.
  • Secure credentials by restricting where accounts and credentials can be used and by using local device credential protection features. 
    • Use virtualizing solutions on modern hardware and software to ensure credentials are securely stored.
    • Ensure storage of clear text passwords in LSASS memory is disabled. Note: For Windows 8, this is enabled by default. For more information see Microsoft Security Advisory Update to Improve Credentials Protection and Management.
    • Consider disabling or limiting NTLM and WDigest Authentication.
    • Implement Credential Guard for Windows 10 and Server 2016 (refer to Microsoft: Manage Windows Defender Credential Guard for more information). For Windows Server 2012R2, enable Protected Process Light for Local Security Authority (LSA).
    • Minimize the AD attack surface to reduce malicious ticket-granting activity. Malicious activity such as “Kerberoasting” takes advantage of Kerberos’ TGS and can be used to obtain hashed credentials that threat actors attempt to crack.
       
VALIDATE SECURITY CONTROLS

In addition to applying mitigations, CISA and FBI recommend exercising, testing, and validating your organization's security program against the threat behaviors mapped to the MITRE ATT&CK for Enterprise framework in this advisory. CISA and FBI recommend testing your existing security controls inventory to assess how they perform against the ATT&CK techniques described in this advisory.

To get started:

  1. Select an ATT&CK technique described in this advisory (see table 1).
  2. Align your security technologies against the technique.
  3. Test your technologies against the technique.
  4. Analyze your detection and prevention technologies performance.
  5. Repeat the process for all security technologies to obtain a set of comprehensive performance data.
  6. Tune your security program, including people, processes, and technologies, based on the data generated by this process.

CISA and FBI recommend continually testing your security program, at scale, in a production environment to ensure optimal performance against the MITRE ATT&CK techniques identified in this advisory.

References Revisions
  • Initial Version: November 16, 2022

This product is provided subject to this Notification and this Privacy & Use policy.

Categories: Security Alerts

AA22-294A: #StopRansomware: Daixin Team

US-CERT Security Alerts - Fri, 10/21/2022 - 06:29
Original release date: October 21, 2022 | Last revised: October 26, 2022
Summary

Actions to take today to mitigate cyber threats from ransomware:

• Install updates for operating systems, software, and firmware as soon as they are released.
• Require phishing-resistant MFA for as many services as possible.
• Train users to recognize and report phishing attempts.

Note: This joint Cybersecurity Advisory (CSA) is part of an ongoing #StopRansomware effort to publish advisories for network defenders that detail various ransomware variants and ransomware threat actors. These #StopRansomware advisories include recently and historically observed tactics, techniques, and procedures (TTPs) and indicators of compromise (IOCs) to help organizations protect against ransomware. Visit stopransomware.gov to see all #StopRansomware advisories and to learn more about other ransomware threats and no-cost resources.

The Federal Bureau of Investigation (FBI), Cybersecurity and Infrastructure Security Agency (CISA), and Department of Health and Human Services (HHS) are releasing this joint CSA to provide information on the “Daixin Team,” a cybercrime group that is actively targeting U.S. businesses, predominantly in the Healthcare and Public Health (HPH) Sector, with ransomware and data extortion operations.

This joint CSA provides TTPs and IOCs of Daixin actors obtained from FBI threat response activities and third-party reporting.

Download the PDF version of this report: pdf, 591 KB

Download the IOCs: .stix 23.2 kb

Technical Details

Note: This advisory uses the MITRE ATT&CK® for Enterprise framework, version 11. See MITRE ATT&CK for Enterprise for all referenced tactics and techniques.

Cybercrime actors routinely target HPH Sector organizations with ransomware:

  • As of October 2022, per FBI Internet Crime Complaint Center (IC3) data, specifically victim reports across all 16 critical infrastructure sectors, the HPH Sector accounts for 25 percent of ransomware complaints.
  • According to an IC3 annual report in 2021, 649 ransomware reports were made across 14 critical infrastructure sectors; the HPH Sector accounted for the most reports at 148.

The Daixin Team is a ransomware and data extortion group that has targeted the HPH Sector with ransomware and data extortion operations since at least June 2022. Since then, Daixin Team cybercrime actors have caused ransomware incidents at multiple HPH Sector organizations where they have:

  • Deployed ransomware to encrypt servers responsible for healthcare services—including electronic health records services, diagnostics services, imaging services, and intranet services, and/or
  • Exfiltrated personal identifiable information (PII) and patient health information (PHI) and threatened to release the information if a ransom is not paid.

Daixin actors gain initial access to victims through virtual private network (VPN) servers. In one confirmed compromise, the actors likely exploited an unpatched vulnerability in the organization’s VPN server [T1190]. In another confirmed compromise, the actors used previously compromised credentials to access a legacy VPN server [T1078] that did not have multifactor authentication (MFA) enabled. The actors are believed to have acquired the VPN credentials through the use of a phishing email with a malicious attachment [T1598.002].

After obtaining access to the victim’s VPN server, Daixin actors move laterally via Secure Shell (SSH) [T1563.001] and Remote Desktop Protocol (RDP) [T1563.002]. Daixin actors have sought to gain privileged account access through credential dumping [T1003] and pass the hash [T1550.002]. The actors have leveraged privileged accounts to gain access to VMware vCenter Server and reset account passwords [T1098] for ESXi servers in the environment. The actors have then used SSH to connect to accessible ESXi servers and deploy ransomware [T1486] on those servers. 

According to third-party reporting, the Daixin Team’s ransomware is based on leaked Babuk Locker source code. This third-party reporting as well as FBI analysis show that the ransomware targets ESXi servers and encrypts files located in /vmfs/volumes/ with the following extensions: .vmdk, .vmem, .vswp, .vmsd, .vmx, and .vmsn. A ransom note is also written to /vmfs/volumes/. See Figure 1 for targeted file system path and Figure 2 for targeted file extensions list. Figure 3 and Figure 4 include examples of ransom notes. Note that in the Figure 3 ransom note, Daixin actors misspell “Daixin” as “Daxin.”

Figure 1: Daixin Team – Ransomware Targeted File Path

Figure 2: Daixin Team – Ransomware Targeted File Extensions

Figure 3: Example 1 of Daixin Team Ransomware Note

Figure 4: Example 2 of Daixin Team Ransomware Note

In addition to deploying ransomware, Daixin actors have exfiltrated data [TA0010] from victim systems. In one confirmed compromise, the actors used Rclone—an open-source program to manage files on cloud storage—to exfiltrate data to a dedicated virtual private server (VPS). In another compromise, the actors used Ngrok—a reverse proxy tool for proxying an internal service out onto an Ngrok domain—for data exfiltration [T1567].

MITRE ATT&CK TACTICS AND TECHNIQUES

See Table 1 for all referenced threat actor tactics and techniques included in this advisory.

Table 1: Daixin Actors’ ATT&CK Techniques for Enterprise

Reconnaissance

Technique Title

ID

Use

Phishing for Information: Spearphishing Attachment

T1598.002

Daixin actors have acquired the VPN credentials (later used for initial access) by a phishing email with a malicious attachment.

Initial Access

Technique Title

ID

Use

Exploit Public-Facing Application

T1190

Daixin actors exploited an unpatched vulnerability in a VPN server to gain initial access to a network.

Valid Accounts

T1078

Daixin actors use previously compromised credentials to access servers on the target network.

Persistence

Technique Title

ID

Use

Account Manipulation

T1098

Daixin actors have leveraged privileged accounts to reset account passwords for VMware ESXi servers in the compromised environment.

Credential Access

Technique Title

ID

Use

OS Credential Dumping

T1003

Daixin actors have sought to gain privileged account access through credential dumping.

Lateral Movement

Technique Title

ID

Use

Remote Service Session Hijacking: SSH Hijacking

T1563.001

Daixin actors use SSH and RDP to move laterally across a network.

Remote Service Session Hijacking: RDP Hijacking

T1563.002

Daixin actors use RDP to move laterally across a network.

Use Alternate Authentication Material: Pass the Hash

T1550.002

Daixin actors have sought to gain privileged account access through pass the hash.

Exfiltration

Technique Title

ID

Use

Exfiltration Over Web Service

T1567

Daixin Team members have used Ngrok for data exfiltration over web servers.

Impact

Technique Title

ID

Use

Data Encrypted for Impact

T1486

Daixin actors have encrypted data on target systems or on large numbers of systems in a network to interrupt availability to system and network resources.

INDICATORS OF COMPROMISE

See Table 2 for IOCs obtained from third-party reporting.

Table 2: Daixin Team IOCs – Rclone Associated SHA256 Hashes

File

SHA256

rclone-v1.59.2-windows-amd64\git-log.txt

9E42E07073E03BDEA4CD978D9E7B44A9574972818593306BE1F3DCFDEE722238

rclone-v1.59.2-windows-amd64\rclone.1

19ED36F063221E161D740651E6578D50E0D3CACEE89D27A6EBED4AB4272585BD

rclone-v1.59.2-windows-amd64\rclone.exe

54E3B5A2521A84741DC15810E6FED9D739EB8083CB1FE097CB98B345AF24E939

rclone-v1.59.2-windows-amd64\README.html

EC16E2DE3A55772F5DFAC8BF8F5A365600FAD40A244A574CBAB987515AA40CBF

rclone-v1.59.2-windows-amd64\README.txt

475D6E80CF4EF70926A65DF5551F59E35B71A0E92F0FE4DD28559A9DEBA60C28

Mitigations

FBI, CISA, and HHS urge HPH Sector organizations to implement the following to protect against Daixin and related malicious activity:

  • Install updates for operating systems, software, and firmware as soon as they are released. Prioritize patching VPN servers, remote access software, virtual machine software, and known exploited vulnerabilities. Consider leveraging a centralized patch management system to automate and expedite the process.
  • Require phishing-resistant MFA for as many services as possible—particularly for webmail, VPNs, accounts that access critical systems, and privileged accounts that manage backups.
  • If you use Remote Desktop Protocol (RDP), secure and monitor it.
    • Limit access to resources over internal networks, especially by restricting RDP and using virtual desktop infrastructure. After assessing risks, if RDP is deemed operationally necessary, restrict the originating sources, and require multifactor authentication (MFA) to mitigate credential theft and reuse. If RDP must be available externally, use a virtual private network (VPN), virtual desktop infrastructure, or other means to authenticate and secure the connection before allowing RDP to connect to internal devices. Monitor remote access/RDP logs, enforce account lockouts after a specified number of attempts to block brute force campaigns, log RDP login attempts, and disable unused remote access/RDP ports.
    • Ensure devices are properly configured and that security features are enabled. Disable ports and protocols that are not being used for business purposes (e.g., RDP Transmission Control Protocol Port 3389).
  • Turn off SSH and other network device management interfaces such as Telnet, Winbox, and HTTP for wide area networks (WANs) and secure with strong passwords and encryption when enabled.
  • Implement and enforce multi-layer network segmentation with the most critical communications and data resting on the most secure and reliable layer.
  • Limit access to data by deploying public key infrastructure and digital certificates to authenticate connections with the network, Internet of Things (IoT) medical devices, and the electronic health record system, as well as to ensure data packages are not manipulated while in transit from man-in-the-middle attacks.
  • Use standard user accounts on internal systems instead of administrative accounts, which allow for overarching administrative system privileges and do not ensure least privilege.
  • Secure PII/PHI at collection points and encrypt the data at rest and in transit by using technologies such as Transport Layer Security (TPS). Only store personal patient data on internal systems that are protected by firewalls, and ensure extensive backups are available if data is ever compromised.
  • Protect stored data by masking the permanent account number (PAN) when it is displayed and rendering it unreadable when it is stored—through cryptography, for example.
  • Secure the collection, storage, and processing practices for PII and PHI, per regulations such as the Health Insurance Portability and Accountability Act of 1996 (HIPAA). Implementing HIPAA security measures can prevent the introduction of malware on the system.
  • Use monitoring tools to observe whether IoT devices are behaving erratically due to a compromise.
  • Create and regularly review internal policies that regulate the collection, storage, access, and monitoring of PII/PHI.
  • In addition, the FBI, CISA, and HHS urge all organizations, including HPH Sector organizations, to apply the following recommendations to prepare for, mitigate/prevent, and respond to ransomware incidents.
Preparing for Ransomware
  • Maintain offline (i.e., physically disconnected) backups of data, and regularly test backup and restoration. These practices safeguard an organization’s continuity of operations or at least minimize potential downtime from a ransomware incident and protect against data losses.
    • Ensure all backup data is encrypted, immutable (i.e., cannot be altered or deleted), and covers the entire organization’s data infrastructure.
  • Create, maintain, and exercise a basic cyber incident response plan and associated communications plan that includes response procedures for a ransomware incident.
    • Organizations should also ensure their incident response and communications plans include response and notification procedures for data breach incidents. Ensure the notification procedures adhere to applicable state laws.
      • Refer to applicable state data breach laws and consult legal counsel when necessary.
      • For breaches involving electronic health information, you may need to notify the Federal Trade Commission (FTC) or the Department of Health and Human Services, and—in some cases—the media. Refer to the FTC’s Health Breach Notification Rule and U.S. Department of Health and Human Services’ Breach Notification Rule for more information.
    • See CISA-Multi-State Information Sharing and Analysis Center (MS-ISAC) Joint Ransomware Guide and CISA Fact Sheet, Protecting Sensitive and Personal Information from Ransomware-Caused Data Breaches, for information on creating a ransomware response checklist and planning and responding to ransomware-caused data breaches.
Mitigating and Preventing Ransomware
  • Restrict Server Message Block (SMB) Protocol within the network to only access servers that are necessary and remove or disable outdated versions of SMB (i.e., SMB version 1). Threat actors use SMB to propagate malware across organizations.
  • Review the security posture of third-party vendors and those interconnected with your organization. Ensure all connections between third-party vendors and outside software or hardware are monitored and reviewed for suspicious activity.
  • Implement listing policies for applications and remote access that only allow systems to execute known and permitted programs.
  • Open document readers in protected viewing modes to help prevent active content from running.
  • Implement user training program and phishing exercises to raise awareness among users about the risks of visiting suspicious websites, clicking on suspicious links, and opening suspicious attachments. Reinforce the appropriate user response to phishing and spearphishing emails.
  • Use strong passwords and avoid reusing passwords for multiple accounts. See CISA Tip Choosing and Protecting Passwords and the National Institute of Standards and Technology’s (NIST’s) Special Publication 800-63B: Digital Identity Guidelines for more information.
  • Require administrator credentials to install software.
  • Audit user accounts with administrative or elevated privileges and configure access controls with least privilege in mind.
  • Install and regularly update antivirus and antimalware software on all hosts.
  • Only use secure networks and avoid using public Wi-Fi networks. Consider installing and using a VPN.
  • Consider adding an email banner to messages coming from outside your organizations.
  • Disable hyperlinks in received emails.
Responding to Ransomware Incidents

If a ransomware incident occurs at your organization:

  • Follow your organization’s Ransomware Response Checklist (see Preparing for Ransomware section).
  • Scan backups. If possible, scan backup data with an antivirus program to check that it is free of malware. This should be performed using an isolated, trusted system to avoid exposing backups to potential compromise.
  • Follow the notification requirements as outlined in your cyber incident response plan.
  • Report incidents to the FBI at a local FBI Field Office, CISA at cisa.gov/report, or the U.S. Secret Service (USSS) at a USSS Field Office.
  • Apply incident response best practices found in the joint Cybersecurity Advisory, Technical Approaches to Uncovering and Remediating Malicious Activity, developed by CISA and the cybersecurity authorities of Australia, Canada, New Zealand, and the United Kingdom.

Note: FBI, CISA, and HHS strongly discourage paying ransoms as doing so does not guarantee files and records will be recovered. Furthermore, payment may also embolden adversaries to target additional organizations, encourage other criminal actors to engage in the distribution of ransomware, and/or fund illicit activities.

REFERENCES
  • Stopransomware.gov is a whole-of-government approach that gives one central location for ransomware resources and alerts.
  • Resource to mitigate a ransomware attack: CISA-Multi-State Information Sharing and Analysis Center (MS-ISAC) Joint Ransomware Guide.
  • No-cost cyber hygiene services: Cyber Hygiene Services and Ransomware Readiness Assessment.
  • Ongoing Threat Alerts and Sector alerts are produced by the Health Sector Cybersecurity Coordination Center (HC3) and can be found at hhs.gov/HC3
  • For additional best practices for Healthcare cybersecurity issues see the HHS 405(d) Aligning Health Care Industry Security Approaches at 405d.hhs.gov 
REPORTING

The FBI is seeking any information that can be shared, to include boundary logs showing communication to and from foreign IP addresses, a sample ransom note, communications with Daixin Group actors, Bitcoin wallet information, decryptor files, and/or a benign sample of an encrypted file. Regardless of whether you or your organization have decided to pay the ransom, the FBI, CISA, and HHS urge you to promptly report ransomware incidents to a local FBI Field Office, or CISA at cisa.gov/report.

ACKNOWLEDGEMENTS

FBI, CISA, and HHS would like to thank CrowdStrike and the Health Information Sharing and Analysis Center (Health-ISAC) for their contributions to this CSA.

DISCLAIMER

The information in this report is being provided “as is” for informational purposes only. FBI, CISA, and HHS do not endorse any commercial product or service, including any subjects of analysis. Any reference to specific commercial products, processes, or services by service mark, trademark, manufacturer, or otherwise, does not constitute or imply endorsement, recommendation, or favoring by FBI, CISA, or HHS.

Revisions
  • Initial Publication: October 21, 2022

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Categories: Security Alerts
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