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YARA · Google Cloud Threat Intelligence (GCTI)

GCTI_Cobaltstrike_Resources_Artifact32_V3_1_And_V3_2

Cobalt Strike's resources/artifact32{.dll,.exe,svc.exe,big.exe,big.dll,bigsvc.exe} and resources/artifact32uac(alt).dll signature for versions 3.1 and 3.2

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/artifact32{.dll,.exe,svc.exe,big.exe,big.dll,bigsvc.exe} and resources/artifact32uac(alt).dll signature for versions 3.1 and 3.2

Associated malware family: Cobalt Strike.

It defines 1 patterns (0 text, 1 hex, 0 regex).

Summary generated from the rule's metadata and condition.

Rule source

cobaltstrike-resources-artifact32-v3-1-and-v3-2.yarApache License 2.0
rule GCTI_Cobaltstrike_Resources_Artifact32_V3_1_And_V3_2
{
	meta:
		description = "Cobalt Strike's resources/artifact32{.dll,.exe,svc.exe,big.exe,big.dll,bigsvc.exe} and resources/artifact32uac(alt).dll signature for versions 3.1 and 3.2"
		author = "gssincla@google.com"
		id = "4fff7f42-9f50-5945-8ec0-2438ac5c7000"
		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_Artifact32_and_Resources_Dropper_v1_45_to_v4_x.yara#L34-L60"
		license_url = "https://github.com/chronicle/GCTI/blob/1c5fd42b1895098527fde00c2d9757edf6b303bb/LICENSE"
		hash = "4f14bcd7803a8e22e81e74d6061d0df9e8bac7f96f1213d062a29a8523ae4624"
		logic_hash = "7a0d33d0260c762b4aa67e4084d7474338c60aa684fd3e622614745d90350da8"
		score = 75
		quality = 85
		tags = ""

	strings:
		$decoderFunc = { 89 ?? B? 04 00 00 00 99 F7 FF 8B [2] 8A [2] 30 ?? 8A ?? 4? 88 }

	condition:
		all of them
}

Strings (1 patterns)

IdentifierTypeValueModifiers
$decoderFunchex{ 89 ?? B? 04 00 00 00 99 F7 FF 8B [2] 8A [2] 30 ?? 8A ?? 4? 88 }

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).

  • 4f14bcd7803a8e22e81e74d6061d0df9e8bac7f96f1213d062a29a8523ae4624

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: 4fff7f42-9f50-5945-8ec0-2438ac5c7000

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