Skip to content

YARA · SEKOIA.IO Community

SEKOIA_Backdoor_Win_Foresttiger

Detect Lazarus' malware ForestTiger

MalwareForest TigerSEKOIA.IO CommunityDetection Rule License 1.1Compiles with YARA-X
Author
Sekoia.io
Date
2023-10-24
Modified
2024-12-19
Score / Quality
75 / 80

What this rule detects

Detect Lazarus' malware ForestTiger

Associated malware family: Forest Tiger.

Targets: Windows PE.

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

Summary generated from the rule's metadata and condition.

Rule source

backdoor-win-foresttiger.yarDetection Rule License 1.1
rule SEKOIA_Backdoor_Win_Foresttiger : FILE
{
	meta:
		description = "Detect Lazarus' malware ForestTiger"
		author = "Sekoia.io"
		id = "d3128da2-a86d-4db8-9b75-2f3048831c7e"
		date = "2023-10-24"
		modified = "2024-12-19"
		reference = "https://www.microsoft.com/en-us/security/blog/2023/10/18/multiple-north-korean-threat-actors-exploiting-the-teamcity-cve-2023-42793-vulnerability/"
		source_url = "https://github.com/SEKOIA-IO/Community/blob/a438a5901a211c2abdf75da9c93921ef187473d1/yara_rules/backdoor_win_foresttiger.yar#L1-L21"
		license_url = "https://github.com/SEKOIA-IO/Community/blob/a438a5901a211c2abdf75da9c93921ef187473d1/LICENSE.md"
		hash = "e06f29dccfe90ae80812c2357171b5c48fba189ae103d28e972067b107e58795"
		hash = "0be1908566efb9d23a98797884f2827de040e4cedb642b60ed66e208715ed4aa"
		logic_hash = "401adaad1597c017c976c5b0b8f67851469c95758779b7691ebb037d0dda9f38"
		score = 75
		quality = 80
		tags = "FILE"
		version = "1.0"
		classification = "TLP:CLEAR"

	strings:
		$ = "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/107.0.0.0 Safari/537.36 Edg/107.0.1418.42"
		$ = "biwbih="
		$ = "rlzbiw="
		$ = "whoami EnDePriv Erro" wide

	condition:
		uint16be( 0 ) == 0x4d5a and all of them
}

Strings (4 patterns)

IdentifierTypeValueModifiers
$text"Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/107.0.0.0 Safari/537.36 Edg/107.0.1418.42"
$text"biwbih="
$text"rlzbiw="
$text"whoami EnDePriv Erro"wide

Condition

uint16be( 0 ) == 0x4d5a and all of them

In plain words (Heuristic)

  • The file must start with “MZ” — a Windows executable (PE).
  • 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.

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).

  • e06f29dccfe90ae80812c2357171b5c48fba189ae103d28e972067b107e58795
  • 0be1908566efb9d23a98797884f2827de040e4cedb642b60ed66e208715ed4aa

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: d3128da2-a86d-4db8-9b75-2f3048831c7e

Metadata

version1.0
classificationTLP:CLEAR

Tags:FILE