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YARA · SEKOIA.IO Community

SEKOIA_Guloader_Lnk_File

LNK file delivering Guloader

GenericSEKOIA.IO CommunityDetection Rule License 1.1Compiles with YARA-X
Author
Sekoia.io
Date
2024-02-07
Modified
2024-12-19
Score / Quality
75 / 80

What this rule detects

LNK file delivering Guloader

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

Summary generated from the rule's metadata and condition.

Rule source

guloader-lnk-file.yarDetection Rule License 1.1
rule SEKOIA_Guloader_Lnk_File : FILE
{
	meta:
		description = "LNK file delivering Guloader"
		author = "Sekoia.io"
		id = "ecc07753-0910-445b-bf84-911b17195894"
		date = "2024-02-07"
		modified = "2024-12-19"
		reference = "https://github.com/SEKOIA-IO/Community"
		source_url = "https://github.com/SEKOIA-IO/Community/blob/a438a5901a211c2abdf75da9c93921ef187473d1/yara_rules/guloader_lnk_file.yar#L1-L18"
		license_url = "https://github.com/SEKOIA-IO/Community/blob/a438a5901a211c2abdf75da9c93921ef187473d1/LICENSE.md"
		logic_hash = "d69038a8b26c7fc7ba7b0968c7c91b589b25512dcf7e3ad5ee56453a4654a1ab"
		score = 75
		quality = 80
		tags = "FILE"
		version = "1.0"
		classification = "TLP:CLEAR"

	strings:
		$s1 = "$PSHOME" wide
		$s2 = "&(${" wide
		$s3 = "}::ToString(" wide
		$s4 = "$([TYPE]${" wide

	condition:
		uint32be( 0 ) == 0x4c000000 and all of them
}

Strings (4 patterns)

IdentifierTypeValueModifiers
$s1text"$PSHOME"wide
$s2text"&(${"wide
$s3text"}::ToString("wide
$s4text"$([TYPE]${"wide

Condition

uint32be( 0 ) == 0x4c000000 and all of them

In plain words (Heuristic)

  • The file must start with the Windows shortcut (LNK) header.
  • All patterns in the rule must match.

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References

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: ecc07753-0910-445b-bf84-911b17195894

Metadata

version1.0
classificationTLP:CLEAR

Tags:FILE