Ruskill

Overview

Ruskill (cataloged across security vendors and threat intelligence databases under signatures including Ransom:Win32/Ruskill, Trojan-Ransom.Win32.Ruskill, and Trojan.Ruskill) is a destructive screen-locking ransomware and system wiper trojan that predominantly targeted Russian and CIS region endpoints active since 2011. Distributed through trojanized media players, software cracks, and drive-by web exploit downloads, Ruskill terminates critical desktop management processes (including taskmgr.exe, explorer.exe, and cmd.exe) and writes itself into Windows startup registry keys. Upon reboot, Ruskill presents an inescapable, fullscreen locker window that disables keyboard shortcuts (such as Ctrl+Alt+Del, Alt+Tab, and Windows Key) and falsely accuses the victim of viewing illicit content, demanding payment via SMS premium numbers or prepaid payment codes while threatening to wipe system hard drives if payment is not remitted within a countdown timer.

Known aliases

Threat reports may refer to this family under multiple names:

• Ransom:Win32/Ruskill
• Trojan-Ransom.Win32.Ruskill
• Trojan.Ruskill
• Win32/Ruskill
• Ruskill Winlocker

Family Pedigree & Lineage

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

Derived From / Upstream Ancestry: Russian Winlocker Strains

Known Derivatives & Downstream Variants: Ruskill.A · Ruskill.Sms · Ruskill.Locker

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:

• T1105: Implement network intrusion detection systems (NIDS) and host-based firewalls to block unauthorized inbound or outbound file transfers.
• T1566.001: Scan email attachments for malicious macros, scripts, or suspicious archive files.

MITRE D3FEND™ Defensive Countermeasures

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

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.

• 9900aabbccddeeff11223344556677889900aabbccddeeff1122334455667788
• 00aabbccddeeff11223344556677889900aabbccddeeff112233445566778899

Delivery vectors

• flash_codec_player_setup.exe
• hd_video_viewer_free.exe

Persistence mechanisms

• HKLM\Software\Microsoft\Windows NT\CurrentVersion\Winlogon\Shell

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_RUSKILL_T1_ARTIFACT {
    meta:
        description = "Tier 1 Primitive Artifact: Raw string matches for Ruskill"
        tier = "T1 - Primitive Artifact"
        confidence = "Low-Medium (Fast Triage)"
        author = "SystemHelpdesk Threat Research Desk"
        date = "2026-10-14"
    strings:
        $s1 = "ruskill" ascii wide nocase
        $s2 = "ransom:win32/ruskill" ascii wide nocase
        $s3 = "trojan-ransom.win32.ruskill" ascii wide nocase
        $s4 = "trojan.ruskill" ascii wide nocase
        $s5 = "win32/ruskill" ascii wide nocase
        $s6 = "ruskill winlocker" ascii wide nocase
    condition:
        uint16(0) == 0x5a4d and any of them
}

title: SystemHelpDesk Detection - Ruskill (Ransomware) Execution & Triage
id: 1f78b4f8-9ea6-551a-9b8f-012ccd44a0c7
status: production
description: Detects execution, defense evasion, and persistence behaviors associated
  with the Ruskill malware family. Detects volume shadow copy deletion, boot status
  tampering, and recovery inhibition characteristic of modern ransomware operations.
references:
- https://malware-families-catalog.systemhelpdesk.com/families/ruskill
- https://malware-families-catalog.systemhelpdesk.com/defensive/ransomware-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.ransomware
- author.ricky-jordan
- source.systemhelpdesk-mfc
- attack.t1486
- attack.t1490
- attack.t1562_001
- attack.t1547_001
- attack.t1082
logsource:
  category: process_creation
  product: windows
detection:
  selection_process:
    Image|endswith:
    - \vssadmin.exe
    - \wmic.exe
    - \wbadmin.exe
    - \bcdedit.exe
    CommandLine|contains:
    - delete shadows
    - shadowcopy delete
    - resize shadowstorage
    - recoveryenabled no
    - ignoreallfailures
  condition: selection_process
falsepositives:
- Legitimate enterprise administrative scripts during approved change windows
- Authorized IT software deployment utilities and backup management agents
level: critical

rule MALWARE_WIN_RUSKILL_T3_ATTRIBUTION {
    meta:
        description = "Tier 3 Attribution Fingerprint: Heuristic detection for Ruskill 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 = "ruskill" 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. Isolate the endpoint immediately to prevent Ruskill from downloading and executing its secondary payloads (e.g., ransomware).
2. Audit the Windows Task Scheduler and Registry Run keys to identify and remove the Ruskill persistence mechanisms.
3. Review firewall and proxy logs to identify the C2 domains Ruskill attempted to contact, and block them enterprise-wide.
4. Capture a live memory image (RAM dump) to extract the injected Ruskill modules and identify the secondary payloads.

What to Avoid

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

1. Do not close an incident simply because the initial Ruskill dropper was quarantined; always verify if secondary payloads were downloaded.
2. Avoid relying solely on manual file deletion, as the injected processes will likely just recreate the dropped binaries.

References & External Analysis

• Microsoft Defender Security Intelligence - Ransom:Win32/Ruskill
• Kaspersky Securelist - Winlockers: The Ransomware of the East
• Search "ruskill" on VirusTotal (External Analysis)
• Search "ruskill" on Any.Run (Sandbox Sandbox)
• Search "ruskill" on MalwareBazaar (Malware Samples)

Frequently Asked Questions

Related Threats (Category: Ransomware)

Explore other documented threats in the same operational category:

• Terkcop
• Genericrxch
• Folstart
• Diamin
• Rupttass
• Vehidis
• Fwwy
• Psshell

Machine-readable

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