Synrat

Overview

SynRAT (also cataloged across malware research archives as Syn-RAT, Backdoor.SynRAT, and SynRAT by DarkCoderSc) is a historically pivotal Delphi-based Remote Access Trojan created in June 2008 by French programmer Jean-Pierre Lesueur ('DarkCoderSc'). Designed as a full-featured administration framework, SynRAT served as the architectural foundation and direct code precursor to DarkComet, one of the most widely weaponized RATs in cybercrime and espionage history. Operating via client-server reverse TCP connections, SynRAT enabled remote operators to bypass NAT and perimeter firewalls. The trojan provided comprehensive surveillance and control capabilities, including live desktop screenshot capture, webcam monitoring, remote process enumeration and injection, registry manipulation, remote command shell execution, and keylogging. SynRAT established persistence through Windows registry Run keys and active desktop shortcuts, demonstrating high operational stealth for its era.

Known aliases

Threat reports may refer to this family under multiple names:

• Syn-RAT
• Backdoor.SynRAT
• SynRAT by DarkCoderSc
• DarkComet Precursor
• Trojan.SynRAT

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: Delphi Rat Architectures

Known Derivatives & Downstream Variants: Synrat 1.0 · Synrat 2.0 · Darkcomet 1.0

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:

• 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.
• T1113: Monitor for frequent or unauthorized screen captures or clipboard reads. Restrict background applications from accessing desktop APIs.
• T1125: Restrict access to local camera or microphone APIs. Utilize endpoint protection that monitors hardware access.

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.

• 7a8b9c0d1e2f3a4b5c6d7e8f9a0b1c2d3e4f5a6b7c8d9e0f1a2b3c4d5e6f7a8b
• 1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6e7f8a9b0c1d2e3f4a5b6c7d8e9f0a1b2c

Delivery vectors

• Underground development forums and direct peer-to-peer executable sharing
• Executable droppers disguised as administrative or gaming tools

Persistence mechanisms

• HKCU\Software\Microsoft\Windows\CurrentVersion\Run\SynRATServer
• %APPDATA%\SynRAT\synrat.exe

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_SYNRAT_T1_ARTIFACT {
    meta:
        description = "Tier 1 Primitive Artifact: Raw string matches for Synrat"
        tier = "T1 - Primitive Artifact"
        confidence = "Low-Medium (Fast Triage)"
        author = "SystemHelpdesk Threat Research Desk"
        date = "2026-10-14"
    strings:
        $s1 = "synrat" ascii wide nocase
        $s2 = "syn-rat" ascii wide nocase
        $s3 = "backdoor.synrat" ascii wide nocase
        $s4 = "synrat by darkcodersc" ascii wide nocase
        $s5 = "darkcomet precursor" ascii wide nocase
        $s6 = "trojan.synrat" ascii wide nocase
    condition:
        uint16(0) == 0x5a4d and any of them
}

title: SystemHelpDesk Detection - Synrat (Trojan) Execution & Triage
id: d54007f8-f956-5ba6-952a-307d1f76b6c5
status: production
description: Detects execution, defense evasion, and persistence behaviors associated
  with the Synrat 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/synrat
- 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.t1059_003
- attack.t1547_001
- attack.t1113
- attack.t1125
- attack.t1071_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_SYNRAT_T3_ATTRIBUTION {
    meta:
        description = "Tier 3 Attribution Fingerprint: Heuristic detection for Synrat 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 = "synrat" 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. Disconnect the affected host from the network to terminate active reverse C2 sessions.
2. Kill the SynRAT server process using Task Manager or Process Explorer.
3. Remove startup registry entries under HKCU\Software\Microsoft\Windows\CurrentVersion\Run.
4. Delete the server executable from %APPDATA% or %TEMP% directories.

What to Avoid

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

1. Do not execute unknown remote administration utilities downloaded from public development forums.
2. Avoid allowing unvetted outbound TCP connections from desktop workstations.

References & External Analysis

• Malware Museum Historical RAT Collection - SynRAT
• DarkComet Official Historical Research Dossier
• Search "synrat" on VirusTotal (External Analysis)
• Search "synrat" on Any.Run (Sandbox Sandbox)
• Search "synrat" on MalwareBazaar (Malware Samples)

Frequently Asked Questions

Related Threats (Category: Trojan)

Explore other documented threats in the same operational category:

• Bebloh
• Perflogger
• Kates
• Redaman
• Cool_Remote_Control
• Genericrxge
• Sphinx
• Game

Machine-readable

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