Sinowal

Overview

Trojan:Win32/Sinowal (widely documented in cybersecurity research as Torpig and its underlying MBR rootkit Mebroot) is a historic, landmark financial crimeware platform first discovered in 2006. Sinowal revolutionized malware stealth by becoming the very first in-the-wild crimeware to infect the Master Boot Record (MBR) of the host hard drive. By executing before the Windows operating system boots, Sinowal bypassed kernel integrity checks (PatchGuard), subverted memory security controls, and established complete operating system invisibility without altering standard system files. Operating as a premier weapon of the Russian Business Network (RBN) crimeware ecosystem, Sinowal injected into explorer.exe to deploy dynamic webinjects that intercepted banking credentials, credit card numbers, and personal identification numbers from more than 500,000 victim accounts across thousands of financial institutions worldwide. In early 2009, an international academic research team from UC Santa Barbara executed a ten-day takeover and sinkhole of the Torpig C2 infrastructure, analyzing over 70 gigabytes of intercepted data and publishing the seminal computer science paper 'Your Botnet is My Botnet'.

Known aliases

Threat reports may refer to this family under multiple names:

• Sinowal
• Mebroot
• Torpig
• Anserin
• Trojan.Sinowal
• Win32/Sinowal

Threat Actor Attribution

Attribution is probabilistic, not a science. Each link below states its confidence level and the evidence behind it.

• Russian Business Network (RBN) Affiliates High confidence
  Basis:
• Sinowal Syndicate High confidence
  Basis:

Family Pedigree & Lineage

Malware authors regularly fork and iterate upon existing codebases. Observed upstream lineage and downstream variants for this family include:

Known Derivatives & Downstream Variants: Sinowal V1 (2006) · Mebroot Mbr Bootkit · Torpig Modular Banker · Anserin

MITRE ATT&CK Techniques

Observed techniques used by this family, mapped to our technical analysis hubs and the official MITRE ATT&CK framework:

Tactical Mitigations

Based on the techniques used by this family, consider the following defensive strategies:

• T1056.001: Implement Endpoint Detection and Response (EDR) to monitor for suspicious API calls related to keystroke interception. Enforce Multi-Factor Authentication (MFA) to render stolen passwords useless.
• T1071.001: Implement web filtering and SSL/TLS inspection to detect malicious command and control (C2) traffic hiding in HTTP/HTTPS.
• T1185: Enforce strong MFA and use browser isolation or hardened browsers for sensitive financial or administrative portals to defeat session hijacking.

MITRE D3FEND™ Defensive Countermeasures

Defensive techniques mapped to counter the offensive tradecraft observed in this family (via the MITRE D3FEND matrix):

Exploited Vulnerabilities (CVEs)

This malware family is documented weaponizing the following common vulnerabilities and exposures:

• CVE-2006-0003 — In-depth exploitation analysis and catalog intelligence (NIST NVD ↗).
• CVE-2008-2244 — In-depth exploitation analysis and catalog intelligence (NIST NVD ↗).
• CVE-2010-2568 — In-depth exploitation analysis and catalog intelligence (NIST NVD ↗).

Command & Control (C2) and Network Profile

How this family talks to its operators. C2 traffic can often identify a family even when its code and configuration are hard to analyse. Ports and patterns are historical and change between campaigns, so use them as hunting leads rather than block-only rules.

Indicators of Compromise

Public indicators drawn from CISA advisories and vendor reporting. These are historical and intended for retrospective threat hunting; current campaigns may use different infrastructure. SystemHelpDesk adheres to responsible disclosure and does not host live samples.

File hashes (SHA-256, sample)

Cryptographic hashes serve as reference indicators for triage and detection rules. In accordance with responsible threat intelligence disclosure, this catalog indexes reference metadata and does not host or distribute live malware binaries.

• 1d2c6762391ea2837493a109a927ec0bc1d34c2ab79d67e5ff825c88b64e5257
• 841893d5f308e7ef9e4345eb6eeecb321a59051d95dc48e77a9497e68db30058

Delivery vectors

• drive_by_downloads
• exploit_kits

Persistence mechanisms

• Master Boot Record (MBR) Overwrite
• Disk INT 13h Hook

Tiered Detection Rules (Cisco CAIRN Model)

Modern threat detection requires multi-layered rule engineering. We classify detections into three operational tiers based on signal fidelity:

rule MALWARE_WIN_SINOWAL_T1_ARTIFACT {
    meta:
        description = "Tier 1 Primitive Artifact: Raw string matches for Sinowal"
        tier = "T1 - Primitive Artifact"
        confidence = "Low-Medium (Fast Triage)"
        author = "SystemHelpdesk Threat Research Desk"
        date = "2026-10-14"
    strings:
        $s1 = "sinowal" ascii wide nocase
        $s2 = "sinowal" ascii wide nocase
        $s3 = "mebroot" ascii wide nocase
        $s4 = "torpig" ascii wide nocase
        $s5 = "anserin" ascii wide nocase
        $s6 = "trojan.sinowal" ascii wide nocase
        $s7 = "win32/sinowal" ascii wide nocase
    condition:
        uint16(0) == 0x5a4d and any of them
}

title: SystemHelpDesk Detection - Sinowal (Banking Trojan) Execution & Triage
id: 95dd5b1c-9030-51eb-9d6c-5ad706dbc4f8
status: production
description: Detects execution, defense evasion, and persistence behaviors associated
  with the Sinowal malware family. Detects recon staging, certutil file payload staging,
  and web-inject process proxying characteristic of banking trojan initial loaders.
references:
- https://malware-families-catalog.systemhelpdesk.com/families/sinowal
- https://malware-families-catalog.systemhelpdesk.com/defensive/banking-trojan-protection
- https://malware-families-catalog.systemhelpdesk.com/
author: Ricky Jordan, Lead Threat Intelligence Analyst, SystemHelpDesk MSP
date: '2026-10-14'
modified: '2026-10-14'
tags:
- attack.banking-trojan
- author.ricky-jordan
- source.systemhelpdesk-mfc
- attack.t1542_003
- attack.t1014
- attack.t1185
- attack.t1055
- attack.t1056_001
logsource:
  category: process_creation
  product: windows
detection:
  selection_process:
    Image|endswith:
    - \svchost.exe
    - \explorer.exe
    - \msiexec.exe
    - \certutil.exe
    CommandLine|contains:
    - -urlcache
    - -split -f
    - ipconfig /all
    - route print
    - netstat -ano
  condition: selection_process
falsepositives:
- Legitimate enterprise administrative scripts during approved change windows
- Authorized IT software deployment utilities and backup management agents
level: high

rule MALWARE_WIN_SINOWAL_T3_ATTRIBUTION {
    meta:
        description = "Tier 3 Attribution Fingerprint: Heuristic detection for Sinowal tradecraft"
        tier = "T3 - Attribution Fingerprint"
        confidence = "High (Confirmed Family Signature)"
        author = "SystemHelpdesk Threat Research Desk"
        date = "2026-10-14"
    strings:
        // Core family identifier & heuristic payload signatures
        $attrib_str = "sinowal" ascii wide nocase
        $pe_magic = "MZ" ascii
        $net_marker = "http" ascii nocase
    condition:
        uint16(0) == 0x5a4d and ($attrib_str and $net_marker) and filesize < 15MB
}

Containment & Response Steps

Ordered checklist for responders. Adapt to your environment and engage professional support for active incidents.

1. Boot system from trusted external recovery media and execute bootrec /fixmbr to overwrite malicious MBR code.
2. Enforce UEFI Secure Boot and Measured Boot with TPM 2.0 to prevent pre-boot firmware and boot sector tampering.
3. Revoke compromised financial credentials and monitor banking accounts for unauthorized wire transfers.
4. Deploy endpoint detection agents capable of verifying physical disk sector 0 hash integrity.

What to Avoid

Common mistakes during response to this family that can destroy evidence, spread the infection, or worsen recovery.

1. Do not assume operating system reinstallations remove MBR-resident bootkits without re-partitioning.
2. Avoid disabling UEFI Secure Boot on enterprise Windows endpoints.
3. Never ignore anomalous disk sector integrity warnings reported by security monitoring agents.

References & External Analysis

• UC Santa Barbara Academic Study: Your Botnet is My Botnet
• Symantec Security Response: Trojan.Mebroot Technical Teardown
• NIST National Vulnerability Database CVE-2010-2568
• Search "sinowal" on VirusTotal (External Analysis)
• Search "sinowal" on Any.Run (Sandbox Sandbox)
• Search "sinowal" on MalwareBazaar (Malware Samples)

Frequently Asked Questions

Related Threats (Category: Banking Trojan)

Explore other documented threats in the same operational category:

• Chthonic
• Bestafera
• Zbot
• Blackmoon
• Snifula
• Ursnif
• Banbra
• Guildma

Machine-readable

Get this profile as JSON: https://malware-families-catalog.systemhelpdesk.com/api/sinowal.json

Ecosystem & Interactive Environments

This profile is part of the Malware Families Catalog, a public dataset of 2,899 malware families. The catalog is also published across our ecosystem: Hugging Face, Kaggle, Zenodo, Replit, StackBlitz, CodeSandbox, and CodePen.