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GCTI_Cobaltstrike_Resources_Bypassuactoken_X64_Dll_V3_11_To_V3_14

Cobalt Strike's resources/bypassuactoken.x64.dll from v3.11 to v3.14 (64-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.x64.dll from v3.11 to v3.14 (64-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-x64-dll-v3-11-to-v3-14.yarApache License 2.0
rule GCTI_Cobaltstrike_Resources_Bypassuactoken_X64_Dll_V3_11_To_V3_14
{
	meta:
		description = "Cobalt Strike's resources/bypassuactoken.x64.dll from v3.11 to v3.14 (64-bit version)"
		author = "gssincla@google.com"
		id = "c89befcd-a622-5947-9ce3-a6031901a45a"
		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_x64_Dll_v3_11_to_v3_14.yara#L17-L118"
		license_url = "https://github.com/chronicle/GCTI/blob/1c5fd42b1895098527fde00c2d9757edf6b303bb/LICENSE"
		hash = "853068822bbc6b1305b2a9780cf1034f5d9d7127001351a6917f9dbb42f30d67"
		logic_hash = "adfd212f2e470f666ab8a2168e976c11d3032c31dab7cf56963dae5fc0f6c5f9"
		score = 75
		quality = 85
		tags = ""

	strings:
		$isHighIntegrityProcess = {
			83 ?? 7A
			75 ??
			8B [3]
			33 ??
			FF 15 [4]
			44 [4]
			8D [2]
			48 8B ??
			48 8D [3]
			48 8B ??
			4C 8B ??
			48 89 [3]
			FF 15 [4]
			85 C0
			74 ??
			48 8B ??
			FF 15 [4]
			8D [2]
			8A ??
			40 [2]
			0F B6 D1
			48 8B 0F
			FF 15 [4]
			81 ?? 00 30 00 00
		}
		$executeTaskmgr = {
			44 8D ?? 70
			48 8D [3]
			E8 [4]
			83 [3] 00
			48 8D [5]
			0F 57 ??
			66 0F 7F [3]
			48 89 [3]
			48 8D [5]
			48 8D [3]
			C7 [3] 70 00 00 00
			C7 [3] 40 00 00 00
			48 89 [3]
			FF 15 
		}

	condition:
		all of them
}

Strings (2 patterns)

IdentifierTypeValueModifiers
$isHighIntegrityProcesshex{ 83 ?? 7A 75 ?? 8B [3] 33 ?? FF 15 [4] 44 [4] 8D [2] 48 8B ?? 48 8D [3] 48 8B ?? 4C 8B ?? 48 89 [3] FF 15 [4] 85 C0 …
$executeTaskmgrhex{ 44 8D ?? 70 48 8D [3] E8 [4] 83 [3] 00 48 8D [5] 0F 57 ?? 66 0F 7F [3] 48 89 [3] 48 8D [5] 48 8D [3] C7 [3] 70 00 00 00 C7 …

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).

  • 853068822bbc6b1305b2a9780cf1034f5d9d7127001351a6917f9dbb42f30d67

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: c89befcd-a622-5947-9ce3-a6031901a45a

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