Skip to content
yararules.org
Menu

YARA · WithSecure Labs IOCs

WITHSECURELABS_Andariel_Starshellrat

Detects StarshellRAT samples

GenericWithSecure Labs IOCsBSD 2-Clause LicenseCompiles with YARA-X
Author
WithSecure
Date
2026-01-22
Score / Quality
75 / 75

What this rule detects

Detects StarshellRAT samples

Targets: Windows PE.

It defines 9 patterns (9 text, 0 hex, 0 regex). YARA modules used: pe.

Summary generated from the rule's metadata and condition.

Rule source

Download .yar

Includes the imports needed to compile it on its own.

andariel-starshellrat.yarBSD 2-Clause License
import "pe"

rule WITHSECURELABS_Andariel_Starshellrat
{
	meta:
		description = "Detects StarshellRAT samples"
		author = "WithSecure"
		id = "ecc377fd-2754-5f6a-a26b-c6c12b9e18c8"
		date = "2026-01-22"
		modified = "2026-01-22"
		reference = "https://github.com/WithSecureLabs/iocs"
		source_url = "https://github.com/WithSecureLabs/iocs/blob/1a8384468dd292c6d2c5114c32e42dc0da1f5ae1/Andariel2025/andariel.yara#L68-L85"
		license_url = "https://github.com/WithSecureLabs/iocs/blob/1a8384468dd292c6d2c5114c32e42dc0da1f5ae1/LICENSE"
		logic_hash = "b210ab8790710a8d53a0775550d94e0604dd80c4681a90dcd093ec8ceccc6da5"
		score = 75
		quality = 75
		tags = ""

	strings:
		$str1 = "StarShell" ascii
		$str2 = "ReadRlt" ascii
		$str3 = "SendRlt" ascii
		$str4 = "ProcessShell" ascii
		$str5 = "Screan ok" wide
		$str6 = "<==>" wide
		$str7 = "\\r\\nStarted..." wide
		$str8 = "\\r\\nDownload End." wide
		$str9 = "\\r\\nupload end" wide

	condition:
		pe.is_pe and 3 of them
}

Strings (9 patterns)

IdentifierTypeValueModifiers
$str1text"StarShell"ascii
$str2text"ReadRlt"ascii
$str3text"SendRlt"ascii
$str4text"ProcessShell"ascii
$str5text"Screan ok"wide
$str6text"<==>"wide
$str7text"\\r\\nStarted..."wide
$str8text"\\r\\nDownload End."wide
$str9text"\\r\\nupload end"wide

Condition

pe.is_pe and 3 of them

In plain words (Heuristic)

  • The file must start with “MZ” — a Windows executable (PE).
  • At least 3 patterns in the rule must match.
  • Uses the pe module.

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

Licence & attribution

Author: WithSecure

Source repository: WithSecure Labs IOCs @ 1a8384468d

Licence: BSD 2-Clause License (repository licence)

Copyright notice: Copyright (c) 2022, WithSecure Oyj

Original rule

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

Rule id: ecc377fd-2754-5f6a-a26b-c6c12b9e18c8

Related rules