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SEKOIA_Infostealer_Win_Lumma_Strings_Aug23

Finds Lumma samples based on the specific strings

MalwareLummaSEKOIA.IO CommunityDetection Rule License 1.1Compiles with YARA-X
Author
Sekoia.io
Date
2023-09-14
Modified
2024-12-19
Score / Quality
75 / 80

What this rule detects

Finds Lumma samples based on the specific strings

Associated malware family: Lumma.

Targets: Windows PE.

It defines 9 patterns (9 text, 0 hex, 0 regex).

Summary generated from the rule's metadata and condition.

Rule source

infostealer-win-lumma-strings-aug23.yarDetection Rule License 1.1
rule SEKOIA_Infostealer_Win_Lumma_Strings_Aug23 : FILE
{
	meta:
		description = "Finds Lumma samples based on the specific strings"
		author = "Sekoia.io"
		id = "728f7825-a463-4b19-b2d3-3460e4c06dc9"
		date = "2023-09-14"
		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_lumma_strings_aug23.yar#L1-L23"
		license_url = "https://github.com/SEKOIA-IO/Community/blob/a438a5901a211c2abdf75da9c93921ef187473d1/LICENSE.md"
		logic_hash = "704a31b0f7c30602305768f13bf6108ebaf08c62451833731d2f2f020efce386"
		score = 75
		quality = 80
		tags = "FILE"
		version = "1.0"
		classification = "TLP:CLEAR"

	strings:
		$str01 = "lid=%s&j=%s&ver" ascii
		$str02 = "%s (%d.%d.%d)" ascii
		$str03 = "- Screen Resoluton:" ascii
		$str04 = "- Physical Installed Memory:" ascii
		$str05 = "Content-Type: attachment/x-object" ascii
		$str06 = "Content-Type: application/x-www-form-urlencoded" ascii
		$str07 = "Content-Type: multipart/form-data; boundary=%s" wide
		$str08 = "SysmonDrv" wide
		$str09 = "TeslaBrowser/5.5" wide

	condition:
		uint16( 0 ) == 0x5A4D and 6 of them
}

Strings (9 patterns)

IdentifierTypeValueModifiers
$str01text"lid=%s&j=%s&ver"ascii
$str02text"%s (%d.%d.%d)"ascii
$str03text"- Screen Resoluton:"ascii
$str04text"- Physical Installed Memory:"ascii
$str05text"Content-Type: attachment/x-object"ascii
$str06text"Content-Type: application/x-www-form-urlencoded"ascii
$str07text"Content-Type: multipart/form-data; boundary=%s"wide
$str08text"SysmonDrv"wide
$str09text"TeslaBrowser/5.5"wide

Condition

uint16( 0 ) == 0x5A4D and 6 of them

In plain words (Heuristic)

  • The file must start with “MZ” — a Windows executable (PE).
  • At least 6 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: 728f7825-a463-4b19-b2d3-3460e4c06dc9

Metadata

version1.0
classificationTLP:CLEAR

Tags:FILE

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