Skip to content

YARA · Volexity threat-intel

VOLEXITY_Malware_Win_Cobaltstrike_D

The CobaltStrike malware family, variant D.

MalwareCobalt StrikeVolexity threat-intelBSD 2-Clause LicenseCompiles with YARA-X
Author
threatintel@volexity.com
Date
2021-05-25
Modified
2024-11-22
Score / Quality
75 / 80

What this rule detects

The CobaltStrike malware family, variant D.

Associated malware family: Cobalt Strike.

It defines 7 patterns (6 text, 1 hex, 0 regex).

Summary generated from the rule's metadata and condition.

Rule source

malware-win-cobaltstrike-d.yarBSD 2-Clause License
rule VOLEXITY_Malware_Win_Cobaltstrike_D : FILE MEMORY
{
	meta:
		description = "The CobaltStrike malware family, variant D."
		author = "threatintel@volexity.com"
		id = "89a2459b-314b-513e-bd1a-8c4239a30338"
		date = "2021-05-25"
		modified = "2024-11-22"
		reference = "https://github.com/volexity/threat-intel"
		source_url = "https://github.com/volexity/threat-intel/blob/3a9d0b52459877ee866a9a0ba06e60059b778c77/2021/2021-05-27 - Suspected APT29 Operation Launches Election Fraud Themed Phishing Campaigns/indicators/yara.yar#L27-L54"
		license_url = "https://github.com/volexity/threat-intel/blob/3a9d0b52459877ee866a9a0ba06e60059b778c77/LICENSE.txt"
		hash = "b041efb8ba2a88a3d172f480efa098d72eef13e42af6aa5fb838e6ccab500a7c"
		logic_hash = "751b6832f2952d369cb616b28ac009d7bfcc4d92bf2db36d87d69bc1e9fa6c75"
		score = 75
		quality = 80
		tags = "FILE, MEMORY"
		os = "win"
		os_arch = "all"
		scan_context = "file,memory"
		severity = "critical"
		license = "See license at https://github.com/volexity/threat-intel/blob/main/LICENSE.txt"
		rule_id = 5445
		version = 5

	strings:
		$s1 = "%s (admin)" fullword
		$s2 = {48 54 54 50 2F 31 2E 31 20 32 30 30 20 4F 4B 0D 0A 43 6F 6E 74 65 6E 74 2D 54 79 70 65 3A 20 61 70 70 6C 69 63 61 74 69 6F 6E 2F 6F 63 74 65 74 2D 73 74 72 65 61 6D 0D 0A 43 6F 6E 74 65 6E 74 2D 4C 65 6E 67 74 68 3A 20 25 64 0D 0A 0D 0A 00}
		$s3 = "%02d/%02d/%02d %02d:%02d:%02d" fullword
		$s4 = "%s as %s\\%s: %d" fullword
		$s5 = "%s&%s=%s" fullword
		$s6 = "rijndael" fullword
		$s7 = "(null)"

	condition:
		6 of ( $s* )
}

Strings (7 patterns)

IdentifierTypeValueModifiers
$s1text"%s (admin)"fullword
$s2hex{48 54 54 50 2F 31 2E 31 20 32 30 30 20 4F 4B 0D 0A 43 6F 6E 74 65 6E 74 2D 54 79 70 65 3A 20 61 70 70 6C 69 63 61 74 69 6F 6E 2F 6F 63 74 65 74 2D 73 74 72 65 …
$s3text"%02d/%02d/%02d %02d:%02d:%02d"fullword
$s4text"%s as %s\\%s: %d"fullword
$s5text"%s&%s=%s"fullword
$s6text"rijndael"fullword
$s7text"(null)"

Condition

6 of ( $s* )

In plain words (Heuristic)

  • At least 6 patterns in ( $s* ) 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).

  • b041efb8ba2a88a3d172f480efa098d72eef13e42af6aa5fb838e6ccab500a7c

Licence & attribution

Author: threatintel@volexity.com

Source repository: Volexity threat-intel @ 3a9d0b5245

Licence: BSD 2-Clause License (stated in the rule's own meta)

“See license at https://github.com/volexity/threat-intel/blob/main/LICENSE.txt”

Copyright notice: Copyright 2022 by Volexity, Inc.

Original rule

Mirrored via YARA Forge 20260927, which prefixes rule names with the source and adds normalised meta fields.

Rule id: 89a2459b-314b-513e-bd1a-8c4239a30338

Metadata

oswin
os_archall
scan_contextfile,memory
severitycritical
rule_id5445
version5

Tags:FILEMEMORY

More Cobalt Strike rules