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GCTI_Cobaltstrike_Resources_Bypassuactoken_Dll_V3_11_To_V3_14

Cobalt Strike's resources/bypassuactoken.dll from v3.11 to v3.14 (32-bit version)

Hack toolCobalt StrikeGoogle Cloud Threat Intelligence (GCTI)Apache License 2.0Compiles with YARA-X
Author
gssincla@google.com
Date
2022-11-18
Modified
2022-11-19
Score / Quality
75 / 85

What this rule detects

Cobalt Strike's resources/bypassuactoken.dll from v3.11 to v3.14 (32-bit version)

Associated malware family: Cobalt Strike.

It defines 2 patterns (0 text, 2 hex, 0 regex).

Summary generated from the rule's metadata and condition.

Rule source

cobaltstrike-resources-bypassuactoken-dll-v3-11-to-v3-14.yarApache License 2.0
rule GCTI_Cobaltstrike_Resources_Bypassuactoken_Dll_V3_11_To_V3_14
{
	meta:
		description = "Cobalt Strike's resources/bypassuactoken.dll from v3.11 to v3.14 (32-bit version)"
		author = "gssincla@google.com"
		id = "b9f25fa5-bd1d-5ba0-9b1d-bb97e1dbf76b"
		date = "2022-11-18"
		modified = "2022-11-19"
		reference = "https://cloud.google.com/blog/products/identity-security/making-cobalt-strike-harder-for-threat-actors-to-abuse"
		source_url = "https://github.com/chronicle/GCTI/blob/1c5fd42b1895098527fde00c2d9757edf6b303bb/YARA/CobaltStrike/CobaltStrike__Resources_Bypassuactoken_Dll_v3_11_to_v3_14.yara#L17-L151"
		license_url = "https://github.com/chronicle/GCTI/blob/1c5fd42b1895098527fde00c2d9757edf6b303bb/LICENSE"
		hash = "df1c7256dfd78506e38c64c54c0645b6a56fc56b2ffad8c553b0f770c5683070"
		logic_hash = "fe0780b7f4c16b55cfa00ea7de4da8ce349ec8a72de763b72e816ebc8e934b6d"
		score = 75
		quality = 85
		tags = ""

	strings:
		$isHighIntegrityProcess = {
			5? 
			5? 
			5? 
			8B ?? 
			6A 19
			5? 
			FF 15 [4]
			85 C0
			75 ?? 
			FF 15 [4]
			83 ?? 7A 
			75 ?? 
			FF [2]
			5? 
			FF 15 [4]
			8B ?? 
			8D [2]
			5? 
			FF [2]
			5? 
			6A 19
			5? 
			FF 15 [4]
			85 C0
			74 ?? 
			FF ?? 
			FF 15 [4]
			8A ?? 
			FE C8
			0F B6 C0
			5? 
			FF ?? 
			FF 15 [4]
			B? 01 00 00 00 
			5? 
			81 ?? 00 30 00 00 
		}
		$executeTaskmgr = {
			6A 3C
			8D ?? C4 
			8B ?? 
			6A 00
			5? 
			8B ?? 
			E8 [4]
			83 C4 0C
			C7 [2] 3C 00 00 00 
			8D [2]
			C7 [2] 40 00 00 00 
			C7 [6]
			C7 [2] 00 00 00 00 
			5? 
			C7 [2] 00 00 00 00 
			C7 [6]
			C7 [2] 00 00 00 00 
			FF 15 [4]
			FF 75 FC
		}

	condition:
		all of them
}

Strings (2 patterns)

IdentifierTypeValueModifiers
$isHighIntegrityProcesshex{ 5? 5? 5? 8B ?? 6A 19 5? FF 15 [4] 85 C0 75 ?? FF 15 [4] 83 ?? 7A 75 ?? FF [2] 5? FF 15 [4] 8B ?? …
$executeTaskmgrhex{ 6A 3C 8D ?? C4 8B ?? 6A 00 5? 8B ?? E8 [4] 83 C4 0C C7 [2] 3C 00 00 00 8D [2] C7 [2] 40 00 00 00 C7 [6] C7 [2] 00 …

Condition

all of them

In plain words (Heuristic)

  • All patterns in the rule must match.

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References

Sample hashes

Hashes of samples the author lists in the rule's meta (look them up in your threat-intelligence platform).

  • df1c7256dfd78506e38c64c54c0645b6a56fc56b2ffad8c553b0f770c5683070

Licence & attribution

Author: gssincla@google.com

Source repository: Google Cloud Threat Intelligence (GCTI) @ 1c5fd42b18

Licence: Apache License 2.0 (repository licence)

Original rule

Mirrored via YARA Forge 20260927, which prefixes rule names with the source and adds normalised meta fields.

Rule id: b9f25fa5-bd1d-5ba0-9b1d-bb97e1dbf76b

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