YARA · Google Cloud Threat Intelligence (GCTI)
GCTI_Cobaltstrike_Resources_Artifact64_V3_14_To_V4_X
Cobalt Strike's resources/artifact64{.exe,.dll,svc.exe,svcbig.exe,big.exe,big.dll,.x64.dll,big.x64.dll} and resource/artifactuac(alt)64.exe signature for versions v3.14 through v4.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/artifact64{.exe,.dll,svc.exe,svcbig.exe,big.exe,big.dll,.x64.dll,big.x64.dll} and resource/artifactuac(alt)64.exe signature for versions v3.14 through v4.x
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
rule GCTI_Cobaltstrike_Resources_Artifact64_V3_14_To_V4_X
{
meta:
= "Cobalt Strike's resources/artifact64{.exe,.dll,svc.exe,svcbig.exe,big.exe,big.dll,.x64.dll,big.x64.dll} and resource/artifactuac(alt)64.exe signature for versions v3.14 through v4.x"
= "gssincla@google.com"
= "1c7731d3-429b-57aa-9c17-8de7d0841b1e"
= "2022-11-18"
= "2022-11-19"
= "https://cloud.google.com/blog/products/identity-security/making-cobalt-strike-harder-for-threat-actors-to-abuse"
= "https://github.com/chronicle/GCTI/blob/1c5fd42b1895098527fde00c2d9757edf6b303bb/YARA/CobaltStrike/CobaltStrike__Resources_Artifact64_v1_49_to_v4_x.yara#L86-L128"
= "https://github.com/chronicle/GCTI/blob/1c5fd42b1895098527fde00c2d9757edf6b303bb/LICENSE"
= "decfcca0018f2cec4a200ea057c804bb357300a67c6393b097d52881527b1c44"
= "af8ba6ba62bf1179510b0940e60f893f61b3ba10c81001dd90fe4c3521e56a37"
= 75
= 85
= ""
strings:
$fmtBuilder = {
41 ?? 5C 00 00 00
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
C7 [3] 5C 00 00 00
C7 [3] 2E 00 00 00
89 [3]
48 [6]
E8
}
$fmtString = "%c%c%c%c%c%c%c%c%cMSSE-%d-server"
condition:
all of them
}
Strings (2 patterns)
| Identifier | Type | Value | Modifiers |
|---|---|---|---|
| $fmtBuilder | hex | { 41 ?? 5C 00 00 00 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 C7 [3] 5C 00 00 00 C7 … | |
| $fmtString | text | "%c%c%c%c%c%c%c%c%cMSSE-%d-server" |
Condition
all of themIn 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.
Sample hashes
Hashes of samples the author lists in the rule's meta (look them up in your threat-intelligence platform).
- decfcca0018f2cec4a200ea057c804bb357300a67c6393b097d52881527b1c44
Licence & attribution
Author: gssincla@google.com
Source repository: Google Cloud Threat Intelligence (GCTI) @ 1c5fd42b18
Licence: Apache License 2.0 (repository licence)
Mirrored via YARA Forge 20260927, which prefixes rule names with the source and adds normalised meta fields.
Rule id: 1c7731d3-429b-57aa-9c17-8de7d0841b1e
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