Liudoor
Overview
Executive Summary
Liudoor is a malicious Backdoor Trojan designed to covertly infiltrate Windows systems, establish stealthy persistence, and provide a remote attacker with unfettered, unauthorized access to the compromised machine. Unlike simple downloaders, a backdoor allows the threat actor to directly interact with the system, execute arbitrary commands, and manually exfiltrate sensitive data.Infection Vector and Technical Capabilities
Liudoor is typically distributed through targeted spear-phishing campaigns containing malicious attachments (often macro-enabled Office documents or weaponized PDFs) or by exploiting unpatched vulnerabilities in public-facing web servers or RDP (Remote Desktop Protocol) endpoints. Once executed, Liudoor focuses on establishing a secure, persistent connection to the attacker:- Command and Control (C2) Communication: The backdoor establishes a connection to a remote C2 server, often over encrypted channels (HTTPS) or via custom protocols on non-standard ports to evade Intrusion Detection Systems (IDS). It actively "listens" for incoming commands.
- Remote Code Execution (RCE): The core functionality of Liudoor is to provide a remote shell. The attacker can execute arbitrary system commands (`cmd.exe` or PowerShell), upload or download files, and manipulate the Windows Registry at will.
- Lateral Movement Facilitation: Because the attacker has interactive control, Liudoor is frequently used as a "beachhead." The attacker will use the compromised host to scan the internal network, dump local credentials (using tools like Mimikatz), and pivot to more valuable servers or Domain Controllers.
Threat Assessment
A Liudoor infection is a critical security incident. The presence of an active backdoor means the network perimeter has completely failed, and a human adversary currently has interactive access to the internal network. Data exfiltration or the deployment of enterprise-wide ransomware is often imminent.Incident Response and Remediation
- Immediate Isolation: The highest priority is to physically disconnect the infected machine from the network to sever the attacker's interactive connection and prevent further lateral movement. Do not power off the machine, as volatile memory (RAM) is required for forensic analysis.
- Forensic Triage: Utilize Endpoint Detection and Response (EDR) or memory forensics to identify the specific processes associated with Liudoor, analyze its network connections to identify the C2 infrastructure, and determine if local administrator credentials have been dumped.
- Enterprise Password Reset and Re-imaging: Because the attacker had interactive access, all credentials used on or accessible from the compromised endpoint must be reset immediately. The endpoint itself must undergo a complete bare-metal wipe and re-image from a trusted baseline.
Known aliases
Threat reports may refer to this family under multiple names:
MITRE ATT&CK Techniques
This family has been observed using the following ATT&CK techniques: T1059.003 T1105 T1573.001 T1021
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.
- T1105: Implement network intrusion detection systems (NIDS) and host-based firewalls to block unauthorized inbound or outbound file transfers.
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_LIUDOOR {
meta:
description = "Detects Liudoor (ransomware)"
author = "SystemHelpdesk Boilerplate Generator"
date = "2026-07-06"
strings:
$s1 = "liudoor" ascii wide nocase
$s2 = "backdoor.liudoor" ascii wide nocase
$s3 = "trojan.liudoor" ascii wide nocase
$s4 = "win32/liudoor" ascii wide nocase
condition:
uint16(0) == 0x5a4d and any of them
}Sigma Rule
title: Suspicious Liudoor Activity
id: 6ab5a73f31b1ed23f09495bff1f05989
status: experimental
description: Detects generic indicators of the liudoor malware family.
logsource:
category: process_creation
product: windows
detection:
selection:
Image|endswith:
- '\cmd.exe'
- '\powershell.exe'
CommandLine|contains:
- "*liudoor*"
- "*backdoor.liudoor*"
- "*trojan.liudoor*"
- "*win32/liudoor*"
condition: selection
level: mediumReferences & External Analysis
- Search "liudoor" on VirusTotal (External Analysis)
Frequently Asked Questions
How do I remove the Liudoor Ransomware from Windows?
Manual removal of Liudoor is highly discouraged as it may leave persistence mechanisms intact. We recommend disconnecting the device from the internet and utilizing a professional incident response service or enterprise-grade EDR software to conduct a full forensic sweep.
Is Liudoor a virus or a Ransomware?
Liudoor is classified as a Ransomware. Unlike traditional viruses that infect files, modern malware like Liudoor typically operates as a standalone payload designed to compromise systems, steal data, or deploy secondary stage implants.
What are the main symptoms of a Liudoor infection?
Symptoms of Liudoor can include unexpected system slowness, unauthorized outbound network traffic to unknown IP addresses, disabled security software, and suspicious background processes running from AppData or Temp directories.
Related Families (Category: ransomware)
Explore other malware families in the same category:
Protect Your Network Against Ransomwares
Want to prevent Liudoor and similar threats from compromising your organization? Read our comprehensive defensive guide: Ransomware Protection Guide.
Machine-readable
Get this profile as JSON: https://jordan123234-malware-families-explorer.static.hf.space/api/liudoor.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.