YARA · SEKOIA.IO Community

SEKOIA_Apt_Muddywater_Powgoop_Loader

Detects the loader of PowGoop malware

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

Author: Sekoia.io
Date: 2022-01-13
Modified: 2024-12-19
Score / Quality: 75 / 80

What this rule detects

Detects the loader of PowGoop malware

It defines 4 patterns (3 text, 1 hex, 0 regex).

Summary generated from the rule's metadata and condition.

Rule source

Download .yar

apt-muddywater-powgoop-loader.yarDetection Rule License 1.1

rule SEKOIA_Apt_Muddywater_Powgoop_Loader : FILE
{
	meta:
		description = "Detects the loader of PowGoop malware"
		author = "Sekoia.io"
		id = "716b45e1-9f17-4546-a003-a7c78340d623"
		date = "2022-01-13"
		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_powgoop_loader.yar#L1-L19"
		license_url = "https://github.com/SEKOIA-IO/Community/blob/a438a5901a211c2abdf75da9c93921ef187473d1/LICENSE.md"
		logic_hash = "70f20928d2bbe081f0595ecdbb6dbe58a2f0807032598d88d829513e6d75287f"
		score = 75
		quality = 80
		tags = "FILE"
		version = "1.0"
		classification = "TLP:CLEAR"

	strings:
		$s1 = "$d.Add($in[$i]);" ascii wide
		$s2 = "[System.Text.Encoding]::UTF8.GetString($o);" ascii wide
		$s3 = "$i+=(1+1)" ascii wide
		$t = { 24 ?? 3d [1-15] 20 24 ?? 3b ?? ?? ?? 20 24 ?? 3b }

	condition:
		filesize < 50KB and ( 3 of ( $s* ) or $t in ( filesize -50 .. filesize ) )
}

Strings (4 patterns)

Identifier	Type	Value	Modifiers
$s1	text	"$d.Add($in[$i]);"	ascii wide
$s2	text	"[System.Text.Encoding]::UTF8.GetString($o);"	ascii wide
$s3	text	"$i+=(1+1)"	ascii wide
$t	hex	{ 24 ?? 3d [1-15] 20 24 ?? 3b ?? ?? ?? 20 24 ?? 3b }

Condition

filesize < 50KB and ( 3 of ( $s* ) or $t in ( filesize -50 .. filesize ) )

In plain words (Heuristic)

The file must be smaller than 50KB (a cheap guard that skips large files).
At least 3 patterns in ( $s* ) must match.
Pattern $t must be found within the range filesize -50 .. filesize.

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References

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

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: 716b45e1-9f17-4546-a003-a7c78340d623

Metadata

version	1.0
classification	TLP:CLEAR

Tags:FILE

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