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[CISA] #StopRansomware: Snatch Ransomware #4135

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SUMMARY

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) and the Cybersecurity and Infrastructure Security Agency (CISA) are releasing this joint CSA to disseminate known ransomware IOCs and TTPs associated with the Snatch ransomware variant identified through FBI investigations as recently as June 1, 2023.

Since mid-2021, Snatch threat actors have consistently evolved their tactics to take advantage of current trends in the cybercriminal space and leveraged successes of other ransomware variants’ operations. Snatch threat actors have targeted a wide range of critical infrastructure sectors including the Defense Industrial Base (DIB), Food and Agriculture, and Information Technology sectors. Snatch threat actors conduct ransomware operations involving data exfiltration and double extortion. After data exfiltration often involving direct communications with victims demanding ransom, Snatch threat actors may threaten victims with double extortion, where the victims’ data will be posted on Snatch’s extortion blog if the ransom goes unpaid.

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

Download the PDF version of this report:

AA23-263A.pdf(PDF, 578.71 KB )

For a downloadable copy of IOCs, see:

AA23-263A STIX XML(XML, 79.84 KB )

AA23-263A STIX JSON(JSON, 56.10 KB )

TECHNICAL DETAILS

Note: This advisory uses the MITRE ATT&CK for Enterprise framework, version 13. 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. For assistance with mapping malicious cyber activity to the MITRE ATT&CK framework, see CISA and MITRE ATT&CK’s Best Practices for MITRE ATT&CK Mapping and CISA’s Decider Tool.

First appearing in 2018, Snatch operates a ransomware-as-a-service (RaaS) model and claimed their first U.S.-based victim in 2019. Originally, the group was referred to as Team Truniger, based on the nickname of a key group member, Truniger, who previously operated as a GandCrab affiliate. Snatch threat actors use a customized ransomware variant notable for rebooting devices into Safe Mode [ T1562.009], enabling the ransomware to circumvent detection by antivirus or endpoint protection, and then encrypting files when few services are running.

Snatch threat actors have been observed purchasing previously stolen data from other ransomware variants in an attempt to further exploit victims into paying a ransom to avoid having their data released on Snatch’s extortion blog. Note: Since November 2021, an extortion site operating under the name Snatch served as a clearinghouse for data exfiltrated or stolen from victim companies on Clearnet and TOR hosted by a bulletproof hosting service. In August 2023, individuals claiming to be associated with the blog gave a media interview claiming the blog was not associated with Snatch ransomware and “none of our targets has been attacked by Ransomware Snatch…”, despite multiple confirmed Snatch victims’ data appearing on the blog alongside victims associated with other ransomware groups, notably Nokoyawa and Conti.[ 1]

Initial Access and Persistence

Snatch threat actors employ several different methods to gain access to and maintain persistence on a victim’s network. Snatch affiliates primarily rely on exploiting weaknesses in Remote Desktop Protocol (RDP) [ T1133] for brute-forcing and gaining administrator credentials to victims’ networks [ T1110.001]. In some instances, Snatch affiliates have sought out compromised credentials from criminal forums/marketplaces [ T1078].

Snatch threat actors gain persistence on a victim’s network by compromising an administrator account [ T1078.002] and establishing connections over port 443 [ T1071.001] to a command and control (C2) server located on a Russian bulletproof hosting service [ T1583.003]. Per IP traffic from event logs provided by recent victims, Snatch threat actors initiated RDP connections from a Russian bulletproof hosting service and through other virtual private network (VPN) services [ T1133].

Data Discovery and Lateral Movement

Snatch threat actors were observed using different TTPs to discover data, move laterally, and search for data to exfiltrate. Snatch threat actors use sc.exe to configure, query, stop, start, delete, and add system services using the Windows Command line. In addition to sc.exe, Snatch threat actors also use tools such as Metasploit and Cobalt Strike [ S0154].

Prior to deploying the ransomware, Snatch threat actors were observed spending up to three months on a victim’s system. Within this timeframe, Snatch threat actors exploited the victim’s network [ T1590], moving laterally across the victim’s network with RDP [ T1021.001] for the largest possible deployment of ransomware and searching for files and folders [ T1005] for data exfiltration [ TA0010] followed by file encryption [ T1486].

Defense Evasion and Execution

During the early stages of ransomware deployment, Snatch threat actors attempt to disable antivirus software [ T1562.001] and run an executable as a file named safe.exe or some variation thereof. In recent victims, the ransomware executable’s name consisted of a string of hexadecimal characters which match the SHA-256 hash of the file in an effort to defeat rule-based detection [ T1036]. Upon initiation, the Snatch ransomware payload queries and modifies registry keys [ T1012][ T1112], uses various native Windows tools to enumerate the system [ T1569.002], finds processes [ T1057], and creates benign processes to execute Windows batch ( .bat) files [ T1059.003]. In some instances, the program attempts to remove all the volume shadow copies from a system [ T1490]. After the execution of the batch files, the executable removes the batch files from the victim’s filesystem [ T1070.004].

The Snatch ransomware executable appends a series of hexadecimal characters to each file and folder name it encrypts—unique to each infection—and leaves behind a text file titled HOW TO RESTORE YOUR FILES.TXT in each folder. Snatch threat actors communicate with their victims through email and the Tox communication platform based on identifiers left in ransom notes or through their extortion blog. Since November 2021, some victims reported receiving a spoofed call from an unknown female who claimed association with Snatch and directed them to the group’s extortion site. In some instances, Snatch victims had a different ransomware variant deployed on their systems, but received a ransom note from Snatch threat actors. As a result, the victims’ data is posted on the ransomware blog involving the different ransomware variant and on the Snatch threat actors’ extortion blog.

Indicators of Compromise (IOCs)

The Snatch IOCs detailed in this section were obtained through FBI investigations from September 2022 through June 2023.

Email Domains and Addresses

Since 2019, Snatch threat actors have used numerous email addresses to email victims. Email addresses used by Snatch threat actors are random but usually originate from one of the following domains listed in Tables 1 and 2:

Table 1: Malicious Email Domains Observed in Use by Snatch Threat Actors

Email Domains

sezname[.]cz

cock[.]li

airmail[.]cc

Table 2 shows a list of legitimate email domains offering encrypted email services that have been used by Snatch threat actors. These email domains are all publicly available and legal. The use of these email domains by a threat actor should not be attributed to the email domains, absent specific articulable facts tending to show they are used at the direction or under the control of a threat actor.

Table 2: Legitimate Email Domains Observed in Use by Snatch Threat Actors

Email Domains

tutanota[.]com / tutamail[.]com / tuta[.]io

mail[.]fr

keemail[.]me

protonmail[.]com / proton[.]me

swisscows[.]email

The email addresses listed in Table 3 were reported by recent victims.

Table 3: Snatch’s Email Addresses Reported by Recent Victims

Email Addresses

sn.tchnews.top@protonmail[.]me

funny385@swisscows[.]email

funny385@proton[.]me

russellrspeck@seznam[.]cz

russellrspeck@protonmail[.]com

Mailz13MoraleS@proton[.]me

datasto100@tutanota[.]com

snatch.vip@protonmail[.]com

TOX Messaging IDs

TOX Messaging IDs

CAB3D74D1DADE95B52928E4D9DFC003FF5ADB2E082F59377D049A91952E8BB3B419DB2FA9D3F

7229828E766B9058D329B2B4BC0EDDD11612CBCCFA4811532CABC76ACF703074E0D1501F8418

83E6E3CFEC0E4C8E7F7B6E01F6E86CF70AE8D4E75A59126A2C52FE9F568B4072CA78EF2B3C97

0FF26770BFAEAD95194506E6970CC1C395B04159038D785DE316F05CE6DE67324C6038727A58

NOTE: According to ransom notes, this is a “Customer service” TOX to reach out to if the original TOX ID does not respond.

Folder Creation

Folder Creation

C:\$SysReset

Filenames with Associated SHA-256 Hashes

Filenames

SHA-256

qesbdksdvnotrjnexutx.bat

0965cb8ee38adedd9ba06bdad9220a35890c2df0e4c78d0559cd6da653bf740f

eqbglqcngblqnl.bat

1fbdb97893d09d59575c3ef95df3c929fe6b6ddf1b273283e4efadf94cdc802d

safe.exe

5950b4e27554585123d7fca44e83169375c6001201e3bf26e57d079437e70bcd

safe.exe

7018240d67fd11847c7f9737eaaae45794b37a5c27ffd02beaacaf6ae13352b3

safe.exe

28e82f28d0b9eb6a53d22983e21a9505ada925ebb61382fabebd76b8c4acff7c

safe.exe

fc31043b5f079ce88385883668eeebba76a62f77954a960fb03bf46f47dbb066

DefenderControl.exe

a201f7f81277e28c0bdd680427b979aee70e42e8a98c67f11e7c83d02f8fe7ae

PRETTYOCEANApplicationdrs.bi

6992aaad3c47b938309fc1e6f37179eb51f028536f8afc02e4986312e29220c0

Setup.exe

510e9fa38a08d446189c34fe6125295f410b36f00aceb65e7b4508e9d7c4e1d1

WRSA.exe

ed0fd61bf82660a69f5bfe0e66457cfe56d66dd2b310e9e97657c37779aef65d

ghnhfglwaplf.bat

2155a029a024a2ffa4eff9108ac15c7db527ca1c8f89ccfd94cc3a70b77cfc57

nllraq.bat

251427c578eaa814f07037fbe6e388b3bc86ed3800d7887c9d24e7b94176e30d

ygariiwfenmqteiwcr.bat

3295f5029f9c9549a584fa13bc6c25520b4ff9a4b2feb1d9e935cc9e4e0f0924

bsfyqgqeauegwyfvtp.bat

6c9d8c577dddf9cc480f330617e263a6ee4461651b4dec1f7215bda77df911e7

rgibdcghzwpk.bat

84e1476c6b21531de62bbac67e52ab2ac14aa7a30f504ecf33e6b62aa33d1fe5

pxyicmajjlqrtgcnhi.bat

a80c7fe1f88cf24ad4c55910a9f2189f1eedad25d7d0fd53dbfe6bdd68912a84

evhgpp.bat

b998a8c15cc19c8c31c89b30f692a40b14d7a6c09233eb976c07f19a84eccb40

eqbglqcngblqnl.bat

1fbdb97893d09d59575c3ef95df3c929fe6b6ddf1b273283e4efadf94cdc802d

qesbdksdvnotrjnexutx.bat

0965cb8ee38adedd9ba06bdad9220a35890c2df0e4c78d0559cd6da653bf740f

HOW TO RESTORE YOUR FILES.TXT

Filenames with Associated SHA-1 Hashes

Filenames

SHA-1

safe.exe

c8a0060290715f266c89a21480fed08133ea2614

Commands Used by Snatch Threat Actors

Commands

wmiadap.exe /F /T /R

%windir%\System32\svchost.eve –k WerSvcGroup

conhost.exe 0xFFFFFFFF -ForceV1

vssadmin delete shadows /all /quiet

bcdedit.exe /set {current} safeboot minimal

REG ADD HKLM\SYSTEM\CurrentControlSet\Control\SafeBoot\Minimal\VSS /VE /T REG_SZ /F /D Service

REG ADD HKLM\SYSTEM\CurrentControlSet\Control\SafeBoot\Minimal\mXoRpcSsx /VE /T REG_SZ /F /D Service

REG QUERY HKLM\SYSTEM\CurrentControlSet\Control /v SystemStartOptions

%CONHOST% "1088015358-1778111623-1306428145949291561678876491840500802412316031-33820320

"C:\Program Files (x86)\Microsoft\Edge\Application\msedge.exe" --flag-switches-begin --flag-switches-end --no-startup-window /prefetch:5

cmd /d /c cmd /d /c cmd /d /c start " " C:\Users\grade1\AppData\Local\PRETTYOCEANluvApplication\PRETTYOCEANApplicationidf.bi.

Registry Keys

Registry Keys

HKLM\SOFTWARE\Microsoft\Windows Media Player NSS\3.0\Servers\D8B548F0-E306-4B2B-BD82-25DAC3208786\FriendlyName

HKU\S-1-5-21-4270068108-2931534202-3907561125-1001\Software\Microsoft\Windows\CurrentVersion\Shell Extensions\Cached\{ED50FC29-B964-

48A9-AFB3-15EBB9B97F36} {ADD8BA80-002B-11D0-8F0F-00C04FD7D062} 0xFFFF

System Log Changes

Source

Message

TerminalServices-RemoteConnectionManager

Remote session from client name exceeded the maximum allowed failed logon attempts. The session was forcibly terminated.

Microsoft-Windows-Windows Firewall With Advanced Security%4Firewall

A rule was added (Event 2004) or modified (Event 2005) in the Windows Defender Firewall exception list. All rules included action “Allow” and rule name included “File and Printer Sharing”

Microsoft-Windows-Windows Firewall With Advanced Security%4Firewall

A Windows Defender Firewall setting was changed in private, public, and domain profile with type “Enable Windows Defender Firewall” and value of “no”.

Microsoft-Windows-TaskScheduler%4Operational

Instance of process C:\Windows\svchost.exe. (Incorrect file location, should be C:\Windows\System32\svchost.exe)

Mutexes Created

Mutexes Created

\Sessions\1\BaseNamedObjects\gcc-shmem-tdm2-fc_key

\Sessions\1\BaseNamedObjects\gcc-shmem-tdm2-sjlj_once

\Sessions\1\BaseNamedObjects\gcc-shmem-tdm2-use_fc_key

gcc-shmem-tdm2-fc_key

gcc-hmem-tdm2-sjlj_once

gcc-shmem-tdm2-use_fc_key

MITRE ATT&CK TACTICS AND TECHNIQUES

See Tables 4-16 for all referenced threat actor tactics and techniques in this advisory.

Table 4: Snatch Threat Actors ATT&CK Techniques for Enterprise – Reconnaissance

Technique Title

ID

Use

Gather Victim Network Information

T1590

Snatch threat actors may gather information about the victim's networks that can be used during targeting.

Table 5: Snatch Threat Actors ATT&CK Techniques for Enterprise – Resource Development

Technique Title

ID

Use

Acquire Infrastructure: Virtual Private Server

T1583.003

Snatch threat actors may rent Virtual Private Servers (VPSs) that can be used during targeting. Snatch threat actors acquire infrastructure from VPS service providers that are known for renting VPSs with minimal registration information, allowing for more anonymous acquisitions of infrastructure.

Table 6: Snatch Threat Actors ATT&CK Techniques for Enterprise – Initial Access

Technique Title

ID

Use

Valid Accounts

T1078

Snatch threat actors use compromised user credentials from criminal forums/marketplaces to gain access and maintain persistence on a victim’s network.

External Remote Services

T1133

Snatch threat actors exploit weaknesses in RDP to perform brute forcing and gain administrator credentials for a victim’s network.

Snatch threat actors use VPN services to connect to a victim’s network.

Table 7: Snatch Threat Actors ATT&CK Techniques for Enterprise – Execution

Technique Title

ID

Use

Command and Scripting Interpreter: Windows Command Shell

T1059.003

Snatch threat actors may use batch files ( .bat) during ransomware execution and data discovery.

System Services: Service Execution

T1569.002

Snatch threat actors may leverage various Windows tools to enumerate systems on the victim’s network. Snatch ransomware used sc.exe.

Table 8: Snatch Threat Actors ATT&CK Techniques for Enterprise – Persistence

Technique Title

ID

Use

Valid Accounts: Domain Accounts

T1078.002

Snatch threat actors compromise domain accounts to maintain persistence on a victim’s network.

Table 9: Snatch Threat Actors ATT&CK Techniques for Enterprise – Defense Evasion

Technique Title

ID

Use

Masquerading

T1036

Snatch threat actors have the ransomware executable match the SHA-256 hash of a legitimate file to avoid rule-based detection.

Indicator Removal: File Deletion

T1070.004

Snatch threat actors delete batch files from a victim’s filesystem once execution is complete.

Modify Registry

T1112

Snatch threat actors modify Windows Registry keys to aid in persistence and execution.

Impair Defenses: Disable or Modify Tools

T1562.001

Snatch threat actors have attempted to disable a system’s antivirus program to enable persistence and ransomware execution.

Impair Defenses: Safe Mode Boot

T1562.009

Snatch threat actors abuse Windows Safe Mode to circumvent detection by antivirus or endpoint protection and encrypt files when few services are running.

Table 10: Snatch Threat Actors ATT&CK Techniques for Enterprise – Credential Access

Technique Title

ID

Use

Brute Force: Password Guessing

T1110.001

Snatch threat actors use brute force to obtain administrator credentials for a victim’s network.

Table 11: Snatch Threat Actors ATT&CK Techniques for Enterprise – Discovery

Technique Title

ID

Use

Query Registry

T1012

Snatch threat actors may interact with the Windows Registry to gather information about the system, configuration, and installed software.

Process Discovery

T1057

Snatch threat actors search for information about running processes on a system.

Table 12: Snatch Threat Actors ATT&CK Techniques for Enterprise – Lateral Movement

Technique Title

ID

Use

Remote Services: Remote Desktop Protocol

T1021.001

Snatch threat actors may use Valid Accounts to log into a computer using the Remote Desktop Protocol.

Table 13: Snatch Threat Actors ATT&CK Techniques for Enterprise – Collection

Technique Title

ID

Use

Data from Local System

T1005

Snatch threat actors search systems to find files and folders of interest prior to exfiltration.

Table 14: Snatch Threat Actors ATT&CK Techniques for Enterprise – Command and Control

Technique Title

ID

Use

Application Layer Protocols: Web Protocols

T1071.001

Snatch threat actors establish connections over port 443 to blend C2 traffic in with other web traffic.

Table 15: Snatch Threat Actors ATT&CK Techniques for Enterprise – Exfiltration

Technique Title

ID

Use

Exfiltration

TA0010

Snatch threat actors use exfiltration techniques to steal data from a victim’s network.

Table 16: Snatch Threat Actors ATT&CK Techniques for Enterprise – Impact

Technique Title

ID

Use

Data Encrypted for Impact

T1486

Snatch threat actors encrypt data on target systems or on large numbers of systems in a network to interrupt availability to system and network resources.

Inhibit System Recovery

T1490

Snatch threat actors delete all volume shadow copies from a victim’s filesystem to inhibit system recovery.

MITIGATIONS

These mitigations apply to all stakeholders. The authoring agencies recommend that software manufactures incorporate secure-by-design and -default principles and tactics into their software development practices for hardening software against ransomware attacks (e.g., to prevent threat actors from using Safe Mode to evade detection and file encryption), thus strengthening the secure posture for their customers.

For more information on secure by design, see CISA’s Secure by Design and Default webpage and joint guide.

The FBI and CISA recommend organizations implement the mitigations below to improve your organization’s cybersecurity posture on the basis of the Snatch threat actor’s activity. These mitigations align with the Cross-Sector Cybersecurity Performance Goals (CPGs) developed by CISA and the National Institute of Standards and Technology (NIST). The CPGs provide a minimum set of practices and protections that CISA and NIST recommend all organizations implement. CISA and NIST based the CPGs on existing cybersecurity frameworks and guidance to protect against the most common and impactful threats, tactics, techniques, and procedures. Visit CISA’s Cross-Sector Cybersecurity Performance Goals for more information on the CPGs, including additional recommended baseline protections.

In addition, the authoring authorities of this CSA recommend network defenders apply the following mitigations to limit potential adversarial use of common system and network discovery techniques, and to reduce the impact and risk of compromise by ransomware or data extortion actors:

VALIDATE SECURITY CONTROLS

In addition to applying mitigations, FBI and CISA 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. FBI and CISA 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 Tables 4-16).
  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.

FBI and CISA 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.

RESOURCES

REPORTING

The FBI is seeking any information that can be shared, to include boundary logs showing communication to and from IP addresses, a sample ransom note, communications with Snatch threat actors, Bitcoin wallet information, decryptor files, and/or a benign sample of an encrypted file. The FBI and CISA strongly discourage 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, the FBI and CISA urge you to promptly report ransomware incidents to the FBI Internet Crime Complaint Center (IC3) at ic3.gov, a local FBI Field Office, or to CISA at report@cisa.gov or (888) 282-0870.

REFERENCES

[1] DataBreaches.net

DISCLAIMER

The information in this report is being provided “as is” for informational purposes only. FBI and CISA do not endorse any commercial entity, 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.

VERSION HISTORY

September 20, 2023: Initial version.

https://www.cisa.gov/news-events/cybersecurity-advisories/aa23-263a

hinoshiba commented 1 year ago

This issue is stale because it has been open 1 day with no activity. Remove stale label or comment or this will be closed in 1 day.

hinoshiba commented 1 year ago

This issue was closed because it has been stale with no activity.