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YARA · SEKOIA.IO Community

SEKOIA_Infostealer_Win_Leaf

Find samples of Leaf Stealer based on specific strings

MalwareSEKOIA.IO CommunityDetection Rule License 1.1Compiles with YARA-X
Author
Sekoia.io
Date
2023-02-07
Modified
2024-12-19
Score / Quality
75 / 80

What this rule detects

Find samples of Leaf Stealer based on specific strings

Targets: Windows PE.

It defines 18 patterns (18 text, 0 hex, 0 regex).

Summary generated from the rule's metadata and condition.

Rule source

infostealer-win-leaf.yarDetection Rule License 1.1
rule SEKOIA_Infostealer_Win_Leaf : FILE
{
	meta:
		description = "Find samples of Leaf Stealer based on specific strings"
		author = "Sekoia.io"
		id = "17d8e384-1092-4f27-b4f7-c0c0f7efcaa3"
		date = "2023-02-07"
		modified = "2024-12-19"
		reference = "https://github.com/SEKOIA-IO/Community"
		source_url = "https://github.com/SEKOIA-IO/Community/blob/a438a5901a211c2abdf75da9c93921ef187473d1/yara_rules/infostealer_win_leaf.yar#L1-L32"
		license_url = "https://github.com/SEKOIA-IO/Community/blob/a438a5901a211c2abdf75da9c93921ef187473d1/LICENSE.md"
		logic_hash = "f8c0ff694c9f7a02613000d85a40f6b400dcca60711e589f7ccd3546f571aea6"
		score = 75
		quality = 80
		tags = "FILE"
		version = "1.0"
		classification = "TLP:CLEAR"

	strings:
		$str01 = "Leaf $tealer" ascii
		$str02 = "KiwiFolder" ascii
		$str03 = "key_wordsFiles" ascii
		$str04 = "**[Click to copy](https://superfurrycdn.nl/copy/" ascii
		$str05 = "Early_Verified_Bot_Developer" ascii
		$str06 = "getCookie.<locals>.<genexpr>" ascii
		$str07 = "C:\\Program Files (x86)\\Steam\\config" ascii
		$str08 = "[crunchyroll](https://crunchyroll.com)" ascii
		$str09 = "-m pip install" ascii
		$str10 = "taskkill /im " ascii
		$str11 = "/loginusers.vdf" ascii
		$str12 = "mot_de_passe" ascii
		$str13 = "Interesting files found on user PC" ascii
		$str14 = "NationsGlory/Local Storage/leveldb" ascii
		$str15 = "wppassw.txt" ascii
		$str16 = "wpcook.txt" ascii
		$str17 = "ProcesName < 1 >" ascii
		$str18 = "Metamask_" ascii

	condition:
		uint16( 0 ) == 0x5A4D and 10 of them
}

Strings (18 patterns)

IdentifierTypeValueModifiers
$str01text"Leaf $tealer"ascii
$str02text"KiwiFolder"ascii
$str03text"key_wordsFiles"ascii
$str04text"**[Click to copy](https://superfurrycdn.nl/copy/"ascii
$str05text"Early_Verified_Bot_Developer"ascii
$str06text"getCookie.<locals>.<genexpr>"ascii
$str07text"C:\\Program Files (x86)\\Steam\\config"ascii
$str08text"[crunchyroll](https://crunchyroll.com)"ascii
$str09text"-m pip install"ascii
$str10text"taskkill /im "ascii
$str11text"/loginusers.vdf"ascii
$str12text"mot_de_passe"ascii
$str13text"Interesting files found on user PC"ascii
$str14text"NationsGlory/Local Storage/leveldb"ascii
$str15text"wppassw.txt"ascii
$str16text"wpcook.txt"ascii
$str17text"ProcesName < 1 >"ascii
$str18text"Metamask_"ascii

Condition

uint16( 0 ) == 0x5A4D and 10 of them

In plain words (Heuristic)

  • The file must start with “MZ” — a Windows executable (PE).
  • At least 10 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: 17d8e384-1092-4f27-b4f7-c0c0f7efcaa3

Metadata

version1.0
classificationTLP:CLEAR

Tags:FILE