{
  "family": "gtbot",
  "sample_count": 1,
  "category": "trojan",
  "description": "<h3>Executive Summary</h3>\nGTBot (often known as Global Threat Bot) is a legacy but highly versatile Trojan and IRC (Internet Relay Chat) Botnet client. Originally prevalent in the early-to-mid 2000s, GTBot was designed to infect Windows systems, connect them to attacker-controlled IRC channels, and wait for centralized commands. The botnet was notorious for its massive scale, primarily utilized to launch devastating Distributed Denial of Service (DDoS) attacks, harvest credentials, and distribute spam.\n\n<h3>Infection Vector and Technical Capabilities</h3>\nGTBot typically spread through malicious email attachments, P2P file-sharing networks (masquerading as legitimate software), or by exploiting unpatched vulnerabilities in Windows services (like DCOM RPC or LSASS) to self-propagate across networks.\n\nUpon execution, GTBot exhibits the classic architecture of an IRC botnet:\n<ul>\n<li><strong>IRC Command and Control:</strong> The bot quietly connects to a hardcoded IRC server and joins a specific, often password-protected, channel. The \"botmaster\" controls the entire infected swarm by typing commands directly into the IRC chat interface.</li>\n<li><strong>DDoS Capabilities:</strong> The primary function of GTBot was its robust DDoS engine. Upon command, the botmaster could direct thousands of infected hosts to simultaneously launch TCP SYN floods, UDP floods, or HTTP GET floods against a target, overwhelming its infrastructure.</li>\n<li><strong>Modular Architecture (mIRC Scripting):</strong> GTBot is actually built upon a modified, hidden version of the legitimate mIRC chat client. Its malicious functionality is driven by highly customized `mIRC.ini` scripts, allowing the botmaster to easily add new capabilities, such as port scanning, keylogging, or downloading secondary malware.</li>\n</ul>\n\n<h3>Threat Assessment</h3>\nWhile pure IRC botnets like GTBot have largely been superseded by HTTP/HTTPS and P2P botnet architectures in modern threat landscapes, a detection indicates a severe compromise. The infected endpoint is actively participating in coordinated attacks against third parties and is completely under the remote control of a cybercriminal.\n\n<h3>Incident Response and Remediation</h3>\n<ul>\n<li><strong>Immediate Network Isolation:</strong> The endpoint must be disconnected from the network immediately to sever the IRC C2 connection, halting its participation in DDoS attacks and preventing the botmaster from executing further commands.</li>\n<li><strong>Firewall Egress Analysis:</strong> Review corporate firewall logs for anomalous outbound connections to known IRC ports (typically TCP 6667, though attackers often use non-standard ports to evade detection). Block these outbound connections to prevent future botnet communications.</li>\n<li><strong>Complete System Rebuild:</strong> Because the botmaster had interactive, command-line control over the endpoint via the IRC backdoor, attempting to clean the system is unreliable. The machine must be wiped to bare metal and re-imaged from a known-good baseline.</li>\n</ul>",
  "cta": "Published by the SystemHelpdesk team.",
  "aliases": [
    "Backdoor.IRC.GTBot",
    "Trojan.GTBot",
    "Win32/GTBot"
  ],
  "enrichment_level": "insufficient_information",
  "faq": [],
  "faq_count": 0,
  "mitre_attack": [
    "T1071.002",
    "T1498.001",
    "T1059.003"
  ],
  "cisa_advisory": null,
  "last_updated": "2026-07-02T07:40:09Z",
  "type": "Trojan / IRC Botnet",
  "target_industries": [
    "Global / Opportunistic"
  ],
  "motivation": "Opportunistic",
  "threat_actors": [
    "Unknown / Cybercriminal"
  ],
  "target_geographies": [
    "Global"
  ]
}