Scarcruft

Overview

Executive Summary

Technical Capabilities and Attack Lifecycle

• Targeted Spear-Phishing: Campaigns begin with meticulously crafted emails containing weaponized documents relevant to the target's geopolitical interests (e.g., inter-Korean relations). These documents exploit vulnerabilities to silently drop the initial payload.
• Custom Tooling (ROKrat/DogCall): ScarCruft heavily relies on a custom, sophisticated Remote Access Trojan (RAT) known as ROKrat (or DogCall). This malware is engineered for deep persistence and extensive intelligence gathering, including keystroke logging, audio recording via the microphone, and stealthy screen captures.
• Covert Exfiltration: To bypass network perimeter defenses, ScarCruft frequently utilizes legitimate cloud services (like Yandex, Dropbox, or pCloud) as their command-and-control (C2) infrastructure. Stolen data is encrypted and silently uploaded to these trusted domains, making the exfiltration traffic incredibly difficult to distinguish from normal user activity.

Threat Impact

Defense and Resilience Strategies

• Rapid Patch Management: Because ScarCruft is known to rapidly weaponize zero-day and N-day vulnerabilities, organizations must maintain an aggressive patching cadence for all operating systems and third-party applications (especially Office and browsers).
• Behavioral Analytics and EDR: Standard antivirus is ineffective against custom ROKrat deployments. Utilize EDR to monitor for anomalous processes spawning from Office applications and unusual, sustained connections to cloud storage APIs.
• Strict Access Controls: Implement Zero Trust principles, enforcing Multi-Factor Authentication (MFA) and limiting the execution of unauthorized binaries to prevent the malware from establishing a foothold, even if an exploit is successfully triggered.

Known aliases

Threat reports may refer to this family under multiple names:

• APT37
• Reaper
• Group123
• ROKrat

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.
• T1059: Restrict execution of scripting languages such as PowerShell, VBScript, or Python to authorized administrators. Enforce Script Block Logging.
• T1125: Restrict access to local camera or microphone APIs. Utilize endpoint protection that monitors hardware access.
• 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):

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_SCARCRUFT_T1_ARTIFACT {
    meta:
        description = "Tier 1 Primitive Artifact: Raw string matches for Scarcruft"
        tier = "T1 - Primitive Artifact"
        confidence = "Low-Medium (Fast Triage)"
        author = "SystemHelpdesk Threat Research Desk"
        date = "2026-10-14"
    strings:
        $s1 = "scarcruft" ascii wide nocase
        $s2 = "apt37" ascii wide nocase
        $s3 = "reaper" ascii wide nocase
        $s4 = "group123" ascii wide nocase
        $s5 = "rokrat" ascii wide nocase
    condition:
        uint16(0) == 0x5a4d and any of them
}

title: SystemHelpDesk Detection - Scarcruft (Trojan) Execution & Triage
id: bb312571-668c-56c2-b77d-93cea8b77a3e
status: production
description: Detects execution, defense evasion, and persistence behaviors associated
  with the Scarcruft malware family. Detects suspicious execution from temporary user
  directories with hidden window flags and background transfer utilities.
references:
- https://malware-families-catalog.systemhelpdesk.com/families/scarcruft
- https://malware-families-catalog.systemhelpdesk.com/defensive/downloader-dropper-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.trojan
- author.ricky-jordan
- source.systemhelpdesk-mfc
- attack.t1566_001
- attack.t1059
- attack.t1567_002
- attack.t1125
- attack.t1056_001
logsource:
  category: process_creation
  product: windows
detection:
  selection_process:
    Image|endswith:
    - \cmd.exe
    - \powershell.exe
    - \cscript.exe
    - \wscript.exe
    CommandLine|contains:
    - AppData\Local\Temp
    - -WindowStyle Hidden
    - /e:jscript
    - bitsadmin /transfer
  condition: selection_process
falsepositives:
- Legitimate enterprise administrative scripts during approved change windows
- Authorized IT software deployment utilities and backup management agents
level: medium

rule MALWARE_WIN_SCARCRUFT_T3_ATTRIBUTION {
    meta:
        description = "Tier 3 Attribution Fingerprint: Heuristic detection for Scarcruft 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 = "scarcruft" 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. Sever network connectivity for the flagged endpoint to terminate persistent command-and-control (C2) communication channels and stop Scarcruft from retrieving secondary stage payloads.
2. Capture process memory triage to detect and terminate malicious threads injected by Scarcruft into legitimate system processes such as explorer.exe or svchost.exe.
3. Audit Windows Registry Run keys (HKCU\Software\Microsoft\Windows\CurrentVersion\Run) and Task Scheduler entries to locate and purge Scarcruft persistence hooks.
4. Deploy updated enterprise EDR detection signatures and conduct an out-of-band endpoint scan to isolate dropped binaries and staged payloads.
5. Rotate all credentials, domain user passwords, and session cookies active on the system during the Scarcruft execution timeframe.

What to Avoid

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

1. Do not assume the incident is resolved simply because an antivirus tool removed the initial Scarcruft dropper; always verify that secondary payloads and persistence hooks have been eradicated.
2. Avoid logging in with Domain Admin or privileged credentials on a machine suspected of running Scarcruft until memory triage is complete.
3. Do not delay host isolation; automated lateral movement and credential dumping can occur within minutes of initial execution.

References & External Analysis

• Search "scarcruft" on VirusTotal (External Analysis)
• Search "scarcruft" on Any.Run (Sandbox Sandbox)
• Search "scarcruft" on MalwareBazaar (Malware Samples)

Frequently Asked Questions

Related Threats (Category: Trojan)

Explore other documented threats in the same operational category:

• Ainslot
• Czyk
• Cardtool
• Dnschanger
• Xmrminer
• Hpursnif
• Ircbrute
• Sinique

Machine-readable

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