Manuscrypt

Overview

Trojan:Win32/Manuscrypt (also known as Volgmer or FALLCHILL) is an extremely sophisticated malware family strongly associated with the North Korean state-sponsored APT group 'Lazarus' (Hidden Cobra). It is a highly customizable, modular implant designed for long-term espionage, data exfiltration, and maintaining persistent, covert access to high-value government, financial, and defense networks (`T1059.003`).

Understanding Manuscrypt (North Korean APT)
To an end-user, Manuscrypt is entirely invisible. For threat intelligence and incident response teams, detecting Manuscrypt is a critical emergency. It indicates a breach by a highly capable, well-resourced nation-state actor whose objectives may range from intellectual property theft to destructive attacks or financial heist (as seen in the SWIFT attacks).

Execution and Espionage Mechanics
Manuscrypt is deployed after initial access is gained (often via targeted spearphishing, exploiting internet-facing vulnerabilities, or watering hole attacks). It is characterized by heavy obfuscation, custom packing routines, and a modular architecture (`T1027.002`). It establishes persistence by disguiring itself as a legitimate Windows Service (often mimicking Microsoft Exchange or IIS services) (`T1543.003`). The malware communicates with its C2 infrastructure using custom, encrypted protocols over HTTP/HTTPS or via compromised proxy servers, blending in with legitimate traffic. It is capable of executing arbitrary commands (`T1059.003`), manipulating files, profiling the system, and deploying destructive modules if the actor chooses.

Indicators of Compromise & Impact
The impact is severe state-sponsored espionage and potential catastrophic damage. Host-based IoCs include EDR alerts for suspicious service creation, highly obfuscated DLLs loaded into legitimate processes (Process Injection), and the presence of custom, encrypted configuration files in the Windows directory. Network IoCs involve encrypted beacons to hardcoded, often compromised legitimate infrastructure (acting as C2 proxies), and anomalous SMB traffic if the actor is pivoting laterally.

MITRE ATT&CK Techniques

Observed techniques used by this family, mapped to the MITRE ATT&CK framework:

Tactical Mitigations

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

• T1059.003: Restrict execution of Windows Command Shell (cmd.exe) and block unauthorized batch scripts.
• T1071.001: Implement web filtering and SSL/TLS inspection to detect malicious command and control (C2) traffic hiding in HTTP/HTTPS.

Generated Detections (Boilerplate)

These YARA and Sigma rules are auto-generated based on the family name and aliases. They must be heavily tuned before deployment in a production environment.

YARA Rule

rule MALWARE_WIN_MANUSCRYPT {
    meta:
        description = "Detects Manuscrypt (trojan)"
        author = "SystemHelpdesk Boilerplate Generator"
        date = "2026-07-06"
    strings:
        $s1 = "manuscrypt" ascii wide nocase
    condition:
        uint16(0) == 0x5a4d and any of them
}

Sigma Rule

title: Suspicious Manuscrypt Activity
id: 5fe7cf0311dafbc17745f2efe87d325c
status: experimental
description: Detects generic indicators of the manuscrypt malware family.
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        Image|endswith:
            - '\cmd.exe'
            - '\powershell.exe'
        CommandLine|contains:
            - "*manuscrypt*"
    condition: selection
level: medium

Containment & Response Steps

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

1. Do not immediately shut down the machine; engage a specialized Incident Response (IR) team immediately. State-sponsored actors require careful handling to preserve volatile memory evidence.
2. Capture a full live memory image (RAM dump) to extract the decrypted Manuscrypt modules, configurations, and C2 routing information.
3. Isolate the endpoint at the network switch level to sever C2 communication while preserving the host state.
4. Initiate a comprehensive, enterprise-wide threat hunt using the extracted IoCs to identify the full scope of the Lazarus Group's intrusion.

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 infection is limited to one machine; Manuscrypt is often just the beachhead for widespread lateral movement.
2. Avoid standard remediation (wiping and reimaging) until the IR team has completed forensic data collection, as this destroys critical evidence of the APT's objectives.

References & External Analysis

• Search "manuscrypt" on VirusTotal (External Analysis)

Frequently Asked Questions

Related Families (Category: trojan)

Explore other malware families in the same category:

• Redaman
• Sharer
• Inexsmar
• Gampass
• Adkdllwrapper

Machine-readable

Get this profile as JSON: https://jordanricky1604-ship-it.github.io/malware-families-catalog/api/manuscrypt.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.