Skip to content

YARA · ditekSHen detection

DITEKSHEN_MALWARE_Win_Isrstealer

ISRStealer payload

MalwareIsr StealerditekSHen detectionBSD 2-Clause LicenseCompiles with YARA-X
Author
ditekSHen
Date
2020-11-06
Modified
2024-11-01
Score / Quality
75 / 75

What this rule detects

ISRStealer payload

Associated malware family: Isr Stealer.

Targets: Windows PE.

It defines 8 patterns (8 text, 0 hex, 0 regex).

Summary generated from the rule's metadata and condition.

Rule source

malware-win-isrstealer.yarBSD 2-Clause License
rule DITEKSHEN_MALWARE_Win_Isrstealer : FILE
{
	meta:
		description = "ISRStealer payload"
		author = "ditekSHen"
		id = "d6c3acdd-e881-5f97-8856-b7b60f56a1c2"
		date = "2020-11-06"
		modified = "2024-11-01"
		reference = "https://github.com/ditekshen/detection"
		source_url = "https://github.com/ditekshen/detection/blob/e76c93dcdedff04076380ffc60ea54e45b313635/yara/malware.yar#L112-L128"
		license_url = "https://github.com/ditekshen/detection/blob/e76c93dcdedff04076380ffc60ea54e45b313635/LICENSE.txt"
		logic_hash = "5dd030ab8122b5dd432168647c7a3465cb3593a326f68b4863a91d16587641e5"
		score = 75
		quality = 75
		tags = "FILE"
		clamav_sig = "MALWARE.Win.Trojan.ISRStealer"

	strings:
		$s1 = "&password=" wide
		$s2 = "&pcname=" wide
		$s3 = "MSVBVM60.DLL" ascii
		$s4 = "MSVBVM60.DLL" wide
		$s5 = "Core Software For : Public" wide
		$s6 = "</Host>" wide
		$s7 = "</Pass>" wide
		$s8 = "/scomma" wide

	condition:
		( uint16( 0 ) == 0x5a4d and filesize < 4000KB and 6 of them ) or all of them
}

Strings (8 patterns)

IdentifierTypeValueModifiers
$s1text"&password="wide
$s2text"&pcname="wide
$s3text"MSVBVM60.DLL"ascii
$s4text"MSVBVM60.DLL"wide
$s5text"Core Software For : Public"wide
$s6text"</Host>"wide
$s7text"</Pass>"wide
$s8text"/scomma"wide

Condition

( uint16( 0 ) == 0x5a4d and filesize < 4000KB and 6 of them ) or all of them

In plain words (Heuristic)

  • The file must start with “MZ” — a Windows executable (PE).
  • The file must be smaller than 4000KB (a cheap guard that skips large files).
  • All patterns in the rule must match.
  • At least 6 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

Licence & attribution

Author: ditekSHen

Source repository: ditekSHen detection @ e76c93dcde

Licence: BSD 2-Clause License (repository licence)

Copyright notice: Copyright 2021 by ditekSHen (https://github.com/ditekshen/detection).

Original rule

Mirrored via YARA Forge 20260927, which prefixes rule names with the source and adds normalised meta fields.

Rule id: d6c3acdd-e881-5f97-8856-b7b60f56a1c2

Metadata

clamav_sigMALWARE.Win.Trojan.ISRStealer

Tags:FILE