YARA · SEKOIA.IO Community

SEKOIA_Apt_Muddywater_Muddyc2Go_Dll_Launcher_Strings

Detects MuddyC2Go DLL launcher

APT / threat actorSEKOIA.IO CommunityDetection Rule License 1.1Compiles with YARA-X

Author: Sekoia.io
Date: 2024-03-07
Modified: 2024-12-19
Score / Quality: 75 / 80

What this rule detects

Detects MuddyC2Go DLL launcher

Targets: Windows PE.

It defines 3 patterns (3 text, 0 hex, 0 regex).

Summary generated from the rule's metadata and condition.

Rule source

Download .yar

apt-muddywater-muddyc2go-dll-launcher-strings.yarDetection Rule License 1.1

rule SEKOIA_Apt_Muddywater_Muddyc2Go_Dll_Launcher_Strings : FILE
{
	meta:
		description = "Detects MuddyC2Go DLL launcher"
		author = "Sekoia.io"
		id = "59756195-d842-4038-8fbf-43d26f4353bc"
		date = "2024-03-07"
		modified = "2024-12-19"
		reference = "https://github.com/SEKOIA-IO/Community"
		source_url = "https://github.com/SEKOIA-IO/Community/blob/a438a5901a211c2abdf75da9c93921ef187473d1/yara_rules/apt_muddywater_muddyc2go_dll_launcher_strings.yar#L1-L20"
		license_url = "https://github.com/SEKOIA-IO/Community/blob/a438a5901a211c2abdf75da9c93921ef187473d1/LICENSE.md"
		hash = "1a0827082d4b517b643c86ee678eaa53f85f1b33ad409a23c50164c3909fdaca"
		logic_hash = "b91653e313258ebd2073a398d0467800056ac94adab02c3a83aa8a379710e4e6"
		score = 75
		quality = 80
		tags = "FILE"
		version = "1.0"
		classification = "TLP:CLEAR"

	strings:
		$ = "-Method GET -ErrorAction Stop;Write-Output $response.Content;iex $response.Content;"
		$ = "GetCurrentProcess"
		$ = "TerminateProcess"

	condition:
		uint16be( 0 ) == 0x4d5a and filesize < 50KB and all of them
}

Strings (3 patterns)

Identifier	Type	Value
$	text	"-Method GET -ErrorAction Stop;Write-Output $response.Content;iex $response.Content;"
$	text	"GetCurrentProcess"
$	text	"TerminateProcess"

Condition

uint16be( 0 ) == 0x4d5a and filesize < 50KB and all of them

In plain words (Heuristic)

The file must start with “MZ” — a Windows executable (PE).
The file must be smaller than 50KB (a cheap guard that skips large files).
All patterns in the rule must match.

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References

https://github.com/SEKOIA-IO/Community

Sample hashes

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

1a0827082d4b517b643c86ee678eaa53f85f1b33ad409a23c50164c3909fdaca

Licence & attribution

Author: Sekoia.io

Source repository: SEKOIA.IO Community @ a438a5901a

Licence: Detection Rule License 1.1 (repository licence)

Original rule

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

Rule id: 59756195-d842-4038-8fbf-43d26f4353bc

Metadata

version	1.0
classification	TLP:CLEAR

Tags:FILE

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