{
  "family": "inexsmar",
  "sample_count": 1,
  "category": "trojan",
  "description": "<h3>Executive Summary</h3>\nInexsmar is a highly customized downloader Trojan primarily known for its role in delivering the Darkhotel APT (Advanced Persistent Threat) malware. It is designed to act as a stealthy, first-stage loader, establishing a foothold on a target system and carefully validating the environment before downloading and executing the more prominent and destructive Darkhotel espionage payloads.\n\n<h3>Infection Vector and Technical Capabilities</h3>\nInexsmar is typically distributed via highly targeted spear-phishing campaigns (often directed at corporate executives or government officials). The emails frequently contain socially engineered lures, such as fake conference invitations or tailored ZIP archives.\n\nUpon execution, Inexsmar employs specific tactics to evade analysis:\n<ul>\n<li><strong>Multi-Stage Unpacking:</strong> Inexsmar utilizes a multi-stage execution process. The initial executable acts as a dropper, extracting a secondary DLL (the core Inexsmar component) and injecting it into a legitimate system process.</li>\n<li><strong>Environment Validation (Anti-Analysis):</strong> Before downloading the final payload, Inexsmar meticulously checks its environment. It looks for the presence of virtualization software (VMware, VirtualBox), debugging tools, and specific antivirus engines. If an analysis environment is detected, execution halts to protect the secondary payload from discovery.</li>\n<li><strong>Secure C2 Communication:</strong> It communicates with its Command and Control (C2) server using customized, encrypted protocols (often mimicking legitimate HTTP traffic) to retrieve the Darkhotel backdoor or keylogger.</li>\n</ul>\n\n<h3>Threat Assessment</h3>\nAn Inexsmar detection is a critical indicator of a targeted, nation-state level attack (APT). Its presence means the organization is actively being targeted for high-value espionage and intellectual property theft. The malware's successful execution likely means the Darkhotel backdoor has already been deployed.\n\n<h3>Incident Response and Remediation</h3>\n<ul>\n<li><strong>Immediate Escalation and Isolation:</strong> A confirmed Inexsmar infection requires immediate escalation to specialized Incident Response teams. The endpoint must be isolated instantly to severe the C2 connection.</li>\n<li><strong>Forensic Hunt for Darkhotel:</strong> Remediation cannot stop at removing Inexsmar. Analysts must conduct a deep forensic sweep of the endpoint and the broader network to locate the Darkhotel payloads it likely downloaded, which often employ rootkit-level persistence.</li>\n<li><strong>Total Re-imaging:</strong> Due to the sophistication of the threat actor, the only secure remediation is a complete bare-metal wipe and re-image from a trusted baseline, alongside a comprehensive review of network security controls and credential resets for the targeted individuals.</li>\n</ul>",
  "cta": "Published by the SystemHelpdesk team.",
  "aliases": [
    "Trojan.Inexsmar",
    "Downloader.Inexsmar",
    "Win32/Inexsmar.A",
    "Darkhotel.Dropper"
  ],
  "enrichment_level": "insufficient_information",
  "faq": [],
  "faq_count": 0,
  "mitre_attack": [
    "T1105",
    "T1055",
    "T1497.001",
    "T1027"
  ],
  "cisa_advisory": null,
  "last_updated": "2026-07-02T07:18:19Z",
  "type": "Trojan / Dropper (APT)",
  "target_industries": [
    "Global / Opportunistic"
  ],
  "motivation": "Opportunistic",
  "threat_actors": [
    "Unknown / Cybercriminal"
  ],
  "target_geographies": [
    "Global"
  ]
}