Skip to content

YARA · Google Cloud Threat Intelligence (GCTI)

GCTI_Cobaltstrike_Resources_Artifact32_And_Resources_Dropper_V1_49_To_V3_14

Cobalt Strike's resources/artifact32{.exe,.dll,big.exe,big.dll} and resources/dropper.exe signature for versions 1.49 to 3.14

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{.exe,.dll,big.exe,big.dll} and resources/dropper.exe signature for versions 1.49 to 3.14

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-and-resources-dropper-v1-49-to-v3-14.yarApache License 2.0
rule GCTI_Cobaltstrike_Resources_Artifact32_And_Resources_Dropper_V1_49_To_V3_14
{
	meta:
		description = "Cobalt Strike's resources/artifact32{.exe,.dll,big.exe,big.dll} and resources/dropper.exe signature for versions 1.49 to 3.14"
		author = "gssincla@google.com"
		id = "243e3761-cbea-561c-97da-f6ba12ebc7ee"
		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#L17-L32"
		license_url = "https://github.com/chronicle/GCTI/blob/1c5fd42b1895098527fde00c2d9757edf6b303bb/LICENSE"
		hash = "40fc605a8b95bbd79a3bd7d9af73fbeebe3fada577c99e7a111f6168f6a0d37a"
		logic_hash = "437706c808bca28384a6e8e24fa3ae120a4ebe4166fa4ca3564c58b881fb23a8"
		score = 75
		quality = 85
		tags = ""

	strings:
		$payloadDecoder = { 8B [2] 89 ?? 03 [2] 8B [2] 03 [2] 0F B6 18 8B [2] 89 ?? C1 ?? 1F C1 ?? 1E 01 ?? 83 ?? 03 29 ?? 03 [2] 0F B6 00 31 ?? 88 ?? 8B [2] 89 ?? 03 [2] 8B [2] 03 [2] 0F B6 12 }

	condition:
		any of them
}

Strings (1 patterns)

IdentifierTypeValueModifiers
$payloadDecoderhex{ 8B [2] 89 ?? 03 [2] 8B [2] 03 [2] 0F B6 18 8B [2] 89 ?? C1 ?? 1F C1 ?? 1E 01 ?? 83 ?? 03 29 ?? 03 [2] 0F B6 00 31 ?? 88 ?? 8B [2] 89 ?? 03 [2] 8B [2] 03 [2] 0 …

Condition

any of them

In plain words (Heuristic)

  • At least one pattern in the rule must match.

Test this rule in your browser

Drop a file to scan it with this rule using YARA-X compiled to WebAssembly. Nothing is uploaded.

Drop a file here or click to chooseScanned locally with YARA-X. Files up to 200 MB.

Open in editor

References

Sample hashes

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

  • 40fc605a8b95bbd79a3bd7d9af73fbeebe3fada577c99e7a111f6168f6a0d37a

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: 243e3761-cbea-561c-97da-f6ba12ebc7ee

More Cobalt Strike rules