Skip to content
yararules.org
Menu

YARA · SEKOIA.IO Community

SEKOIA_Trojan_Win_Bbtok_Iso_Sep23

Finds BBTok installation ISO file

MalwareSEKOIA.IO CommunityDetection Rule License 1.1Compiles with YARA-X (with warnings)
Author
Sekoia.io
Date
2023-09-26
Modified
2024-12-19
Score / Quality
75 / 78

What this rule detects

Finds BBTok installation ISO file

It defines 5 patterns (4 text, 1 hex, 0 regex).

YARA-X says: warning[text_as_hex]: hex pattern could be written as text literal

Summary generated from the rule's metadata and condition.

Rule source

Download .yar
trojan-win-bbtok-iso-sep23.yarDetection Rule License 1.1
rule SEKOIA_Trojan_Win_Bbtok_Iso_Sep23 : FILE
{
	meta:
		description = "Finds BBTok installation ISO file"
		author = "Sekoia.io"
		id = "6032853d-b872-4b2e-913d-366e7f3d0f32"
		date = "2023-09-26"
		modified = "2024-12-19"
		reference = "https://research.checkpoint.com/2023/behind-the-scenes-of-bbtok-analyzing-a-bankers-server-side-components/"
		source_url = "https://github.com/SEKOIA-IO/Community/blob/a438a5901a211c2abdf75da9c93921ef187473d1/yara_rules/trojan_win_bbtok_iso_sep23.yar#L1-L22"
		license_url = "https://github.com/SEKOIA-IO/Community/blob/a438a5901a211c2abdf75da9c93921ef187473d1/LICENSE.md"
		hash = "140e83d2e0d012cdd5625ea89c3b3af05a80877cfc8215bbe20823e7e88c80b1"
		logic_hash = "efef1e4e50d84cd30c025c86beb751c73a996cca896f90729571f48259ffc110"
		score = 75
		quality = 78
		tags = "FILE"
		version = "1.0"
		classification = "TLP:CLEAR"

	strings:
		$iso = {43 44 30 30 31}
		$str01 = "POWERISO" ascii
		$str02 = "%ProgramFiles(x86)%\\Microsoft\\Edge\\Application\\msedge.exe" ascii wide
		$str03 = ".pdf /Y & start" wide
		$str04 = "\\MSBuild.exe -nologo \\\\" ascii wide

	condition:
		all of them and filesize < 500KB
}

Strings (5 patterns)

IdentifierTypeValueModifiers
$isohex{43 44 30 30 31}
$str01text"POWERISO"ascii
$str02text"%ProgramFiles(x86)%\\Microsoft\\Edge\\Application\\msedge.exe"ascii wide
$str03text".pdf /Y & start"wide
$str04text"\\MSBuild.exe -nologo \\\\"ascii wide

Condition

all of them and filesize < 500KB

In plain words (Heuristic)

  • The file must be smaller than 500KB (a cheap guard that skips large files).
  • 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).

  • 140e83d2e0d012cdd5625ea89c3b3af05a80877cfc8215bbe20823e7e88c80b1

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: 6032853d-b872-4b2e-913d-366e7f3d0f32

Metadata

version1.0
classificationTLP:CLEAR

Tags:FILE

Related rules