Skip to content

YARA · Google Cloud Threat Intelligence (GCTI)

GCTI_Cobaltstrike_Resources_Artifact32_V3_14_To_V4_X

Cobalt Strike's resources/artifact32{.dll,.exe,big.exe,big.dll,bigsvc.exe} signature for versions 3.14 to 4.x and resources/artifact32svc.exe for 3.14 to 4.x and resources/artifact32uac.dll for v3.14 and v4.0

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,big.exe,big.dll,bigsvc.exe} signature for versions 3.14 to 4.x and resources/artifact32svc.exe for 3.14 to 4.x and resources/artifact32uac.dll for v3.14 and v4.0

Associated malware family: Cobalt Strike.

It defines 2 patterns (1 text, 1 hex, 0 regex).

Summary generated from the rule's metadata and condition.

Rule source

cobaltstrike-resources-artifact32-v3-14-to-v4-x.yarApache License 2.0
rule GCTI_Cobaltstrike_Resources_Artifact32_V3_14_To_V4_X
{
	meta:
		description = "Cobalt Strike's resources/artifact32{.dll,.exe,big.exe,big.dll,bigsvc.exe} signature for versions 3.14 to 4.x and resources/artifact32svc.exe for 3.14 to 4.x and resources/artifact32uac.dll for v3.14 and v4.0"
		author = "gssincla@google.com"
		id = "8a010305-dce5-55f4-b2dd-a736721efe22"
		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#L62-L89"
		license_url = "https://github.com/chronicle/GCTI/blob/1c5fd42b1895098527fde00c2d9757edf6b303bb/LICENSE"
		hash = "888bae8d89c03c1d529b04f9e4a051140ce3d7b39bc9ea021ad9fc7c9f467719"
		logic_hash = "fc5c353c568e33df80fa5bab14d11112ca211e269043b83dba8b7d1a6a008a7b"
		score = 75
		quality = 85
		tags = ""

	strings:
		$pushFmtStr = {	C7 [3] 5C 00 00 00 C7 [3] 65 00 00 00 C7 [3] 70 00 00 00 C7 [3] 69 00 00 00 C7 [3] 70 00 00 00 F7 F1 C7 [3] 5C 00 00 00  C7 [3] 2E 00 00 00 C7 [3] 5C 00 00 00 }
		$fmtStr = "%c%c%c%c%c%c%c%c%cMSSE-%d-server"

	condition:
		all of them
}

Strings (2 patterns)

IdentifierTypeValueModifiers
$pushFmtStrhex{ C7 [3] 5C 00 00 00 C7 [3] 65 00 00 00 C7 [3] 70 00 00 00 C7 [3] 69 00 00 00 C7 [3] 70 00 00 00 F7 F1 C7 [3] 5C 00 00 00 C7 [3] 2E 00 00 00 C7 [3] 5C 00 00 00 …
$fmtStrtext"%c%c%c%c%c%c%c%c%cMSSE-%d-server"

Condition

all of them

In plain words (Heuristic)

  • All patterns 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).

  • 888bae8d89c03c1d529b04f9e4a051140ce3d7b39bc9ea021ad9fc7c9f467719

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: 8a010305-dce5-55f4-b2dd-a736721efe22

More Cobalt Strike rules