Pcclient
Table of Contents
Overview
PcClient (classified across threat intelligence repositories under signatures including Backdoor:Win32/PcClient, Trojan:Win32/PcClient, and linked to the prolific Chinese open-source remote access trojan framework PcShare) is a landmark Windows remote access trojan and backdoor active since 2008. Widely adopted by diverse Chinese cyber espionage groups (including APT threat actors) and cybercriminal syndicates, PcClient provides extensive remote administration and surveillance capabilities. Once executed, PcClient installs persistence by creating a background service or registry Run key, connects to remote command-and-control servers using custom binary protocols, and provides operators with interactive command shell access, real-time desktop screen monitoring, keyboard logging, file uploading and downloading, process manipulation, and SOCKS proxy pivoting across compromised internal corporate networks.
Known aliases
Threat reports may refer to this family under multiple names:
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: Pcshare Rat Framework
Known Derivatives & Downstream Variants: Backdoor:Win32/Pcclient.A · Backdoor:Win32/Pcclient.B
MITRE ATT&CK Techniques
This family has been observed using the following ATT&CK techniques: T1059.003 · T1056.001 · T1113 · T1090 · T1547.001
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.
- T1059.003: Restrict execution of Windows Command Shell (cmd.exe) and block unauthorized batch scripts.
- T1113: Monitor for frequent or unauthorized screen captures or clipboard reads. Restrict background applications from accessing desktop APIs.
MITRE D3FEND™ Defensive Countermeasures
Defensive techniques mapped to counter the offensive tradecraft observed in this family (via the MITRE D3FEND matrix):
| D3FEND ID | Countermeasure Name | Tactic | Countered ATT&CK | Defensive Guidance |
|---|---|---|---|---|
D3-MFA | Multi-factor Authentication | Harden | T1056.001 | Enforce FIDO2 / WebAuthn physical tokens to render keystroke-intercepted passwords useless. |
D3-PBA | Process Spawn Analysis | Detect | T1059.003 | Inspect command-line arguments and anomalous parent-child relationships spawning from cmd.exe. |
D3-OAA | Outbound Network Traffic Filtering | Isolate | T1090 | Restrict outbound connections to known external proxy relays and enforce enterprise forward proxy authentication. |
D3-SD | Screen Capture Detection | Detect | T1113 | Monitor desktop graphics API calls (BitBlt, GetDC) triggered by non-standard background threads. |
D3-RPM | Registry Persistence Monitoring | Detect | T1547.001 | Audit and restrict write privileges to user and machine-level Registry Run/RunOnce keys using Endpoint Privilege Management. |
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:
Tier 1 Primitive Artifact Rule (Fast Triage)
Matches raw strings and file markers. Vulnerable to binary repacking and simple obfuscation.
rule MALWARE_WIN_PCCLIENT_T1_ARTIFACT {
meta:
description = "Tier 1 Primitive Artifact: Raw string matches for Pcclient"
tier = "T1 - Primitive Artifact"
confidence = "Low-Medium (Fast Triage)"
author = "SystemHelpdesk Threat Research Desk"
date = "2026-10-14"
strings:
$s1 = "pcclient" ascii wide nocase
$s2 = "backdoor:win32/pcclient" ascii wide nocase
$s3 = "trojan:win32/pcclient" ascii wide nocase
$s4 = "backdoor.win32.pcclient" ascii wide nocase
$s5 = "win32/pcclient" ascii wide nocase
$s6 = "pcshare rat" ascii wide nocase
$s7 = "backdoor.pcclient" ascii wide nocase
condition:
uint16(0) == 0x5a4d and any of them
}Tier 2 Behavioral Context Rule (Process Chains & Sigma)
Tracks parent-child process anomalies and suspicious scripting telemetry. Resilient against file renames.
title: SystemHelpDesk Detection - Pcclient (Rat) Execution & Triage
id: 5fe98468-6e10-57c2-9c9a-596e709d9ad6
status: production
description: Detects execution, defense evasion, and persistence behaviors associated
with the Pcclient malware family. Detects unauthorized persistence creation via
Windows Registry Run keys, scheduled tasks, and privilege escalation indicative
of RAT installations.
references:
- https://malware-families-catalog.systemhelpdesk.com/families/pcclient
- https://malware-families-catalog.systemhelpdesk.com/defensive/backdoor-rat-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.rat
- author.ricky-jordan
- source.systemhelpdesk-mfc
- attack.t1059_003
- attack.t1056_001
- attack.t1113
- attack.t1090
- attack.t1547_001
logsource:
category: process_creation
product: windows
detection:
selection_process:
Image|endswith:
- \reg.exe
- \schtasks.exe
- \cmd.exe
- \powershell.exe
CommandLine|contains:
- \CurrentVersion\Run
- /create /tn
- bypass -enc
- net user /add
- net localgroup administrators
condition: selection_process
falsepositives:
- Legitimate enterprise administrative scripts during approved change windows
- Authorized IT software deployment utilities and backup management agents
level: highTier 3 Attribution Fingerprint Rule (High Fidelity)
Deep signature matching distinctive operational fingerprints and payload characteristics.
rule MALWARE_WIN_PCCLIENT_T3_ATTRIBUTION {
meta:
description = "Tier 3 Attribution Fingerprint: Heuristic detection for Pcclient 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 = "pcclient" 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
}References & External Analysis
- Microsoft Defender Threat Encyclopedia - Backdoor:Win32/PcClient
- Trend Micro Threat Encyclopedia - Backdoor.Win32.PcClient
- Search "pcclient" on VirusTotal (External Analysis)
- Search "pcclient" on Any.Run (Sandbox Sandbox)
- Search "pcclient" on MalwareBazaar (Malware Samples)
Frequently Asked Questions
What is Backdoor:Win32/PcClient (PcShare)?
PcClient is a prominent modular Windows remote access trojan derived from the PcShare codebase, widely utilized in cyber espionage and crimeware operations.
What surveillance modules are included in PcClient?
PcClient includes live screen streaming, keystroke logging, microphone audio surveillance, file system browsing, and remote command shell execution.
How does PcClient maintain persistence on Windows?
It installs itself as a Windows background service or registers autorun entries in the Windows CurrentVersion\Run registry key.
How do threat actors use PcClient for lateral movement?
PcClient includes a built-in SOCKS proxy server module, enabling remote operators to pivot through the infected host into internal network subnets.
How can enterprise security teams detect PcClient?
Monitor for anomalous outbound TCP connections on non-standard ports, detect unauthorized service registrations, and inspect injected processes with EDR.
How do I remove the Pcclient Rat from Windows?
Manual removal of Pcclient 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 Pcclient a virus or a Rat?
Pcclient is classified as a Rat. Unlike traditional viruses that infect files, modern malware like Pcclient typically operates as a standalone payload designed to compromise systems, steal data, or deploy secondary stage implants.
What are the main symptoms of a Pcclient infection?
Symptoms of Pcclient 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.
Protect Your Network Against Rats
Want to prevent Pcclient and similar threats from compromising your organization? Read our comprehensive defensive guide: Backdoor & RAT Protection for Businesses.
📣 Threat Intel Correction or Update?
Notice an outdated IOC, unlisted alias, or disputed attribution? Threat researchers are invited to propose an update on GitHub or contact the SystemHelpDesk research desk. All community revisions are credited in our public CHANGELOG.
Machine-readable
Get this profile as JSON: https://malware-families-catalog.systemhelpdesk.com/api/pcclient.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.