CVE-2021-31979 CVE-2021-33771 Exploits by Sourgum

 1title: CVE-2021-31979 CVE-2021-33771 Exploits by Sourgum
 2id: ad7085ac-92e4-4b76-8ce2-276d2c0e68ef
 3status: test
 4description: Detects patterns as noticed in exploitation of Windows CVE-2021-31979 CVE-2021-33771 vulnerability and DevilsTongue malware by threat group Sourgum
 5references:
 6    - https://www.microsoft.com/security/blog/2021/07/15/protecting-customers-from-a-private-sector-offensive-actor-using-0-day-exploits-and-devilstongue-malware/
 7    - https://citizenlab.ca/2021/07/hooking-candiru-another-mercenary-spyware-vendor-comes-into-focus/
 8author: Sittikorn S
 9date: 2021-07-16
10modified: 2022-10-09
11tags:
12    - attack.credential-access
13    - attack.t1566
14    - attack.t1203
15    - cve.2021-33771
16    - cve.2021-31979
17    - detection.emerging-threats
18    # - threat_group.Sourgum
19logsource:
20    product: windows
21    category: file_event
22detection:
23    selection:
24        TargetFilename|contains:
25            - 'C:\Windows\system32\physmem.sys'
26            - 'C:\Windows\System32\IME\IMEJP\imjpueact.dll'
27            - 'C:\Windows\system32\ime\IMETC\IMTCPROT.DLL'
28            - 'C:\Windows\system32\ime\SHARED\imecpmeid.dll'
29            - 'C:\Windows\system32\config\spp\ServiceState\Recovery\pac.dat'
30            - 'C:\Windows\system32\config\cy-GB\Setup\SKB\InputMethod\TupTask.dat'
31            - 'C:\Windows\system32\config\config\startwus.dat'
32            - 'C:\Windows\system32\ime\SHARED\WimBootConfigurations.ini'
33            - 'C:\Windows\system32\ime\IMEJP\WimBootConfigurations.ini'
34            - 'C:\Windows\system32\ime\IMETC\WimBootConfigurations.ini'
35    condition: selection
36falsepositives:
37    - Unlikely
38level: critical

References

• https://www.microsoft.com/security/blog/2021/07/15/protecting-customers-from-a-private-sector-offensive-actor-using-0-day-exploits-and-devilstongue-malware/

  
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