{
  "family": "zacinlo",
  "sample_count": 1,
  "category": "advanced_threat",
  "description": "<h3>Executive Summary</h3>\nZacinlo is a highly sophisticated Adware and Rootkit framework. Unlike standard adware that relies on simple browser extensions, Zacinlo utilizes advanced rootkit techniques to deeply embed itself into the Windows operating system. Its primary objective is to invisibly intercept web traffic, inject highly persistent advertisements, and perform \"click fraud\" while actively defending itself against removal by security software.\n\n<h3>Infection Vector and Technical Capabilities</h3>\nZacinlo is typically distributed via malicious installers masquerading as VPN software or legitimate utilities on third-party download sites. \n\nUpon execution, Zacinlo demonstrates capabilities typically reserved for advanced nation-state malware:\n<ul>\n<li><strong>Rootkit Capabilities (Driver Installation):</strong> Zacinlo's defining feature is the installation of a malicious kernel-mode driver (often signed with stolen or fake certificates). This driver allows the adware to operate at the deepest level of the OS (Ring 0), hiding its files, processes, and registry keys from standard user-mode antivirus scanners.</li>\n<li><strong>Man-in-the-Browser (MitB):</strong> The adware intercepts all HTTPS web traffic using a custom root certificate. It injects its own JavaScript into web pages to overlay ads, replace legitimate ads with its own, and simulate invisible clicks on advertisements to generate fraudulent revenue (click fraud).</li>\n<li><strong>Active Self-Defense:</strong> The rootkit actively monitors the system for common security tools (like Malwarebytes or Windows Defender). If it detects an attempt to terminate its processes or delete its files, the driver will actively block the action or immediately restore the deleted components.</li>\n</ul>\n\n<h3>Threat Assessment</h3>\nZacinlo is a severe threat. While its current motive is financial (ad fraud), the presence of a malicious, ring-0 rootkit on an endpoint means the system is fundamentally compromised. The same infrastructure could easily be repurposed to deploy destructive malware or exfiltrate sensitive data completely invisibly.\n\n<h3>Incident Response and Remediation</h3>\n<ul>\n<li><strong>Avoid Standard Uninstallation:</strong> Standard Control Panel removal or basic antivirus scans will fail and often trigger the rootkit's self-defense mechanisms, potentially causing system instability (BSODs).</li>\n<li><strong>Specialized Anti-Rootkit Tools:</strong> Remediation requires booting into a dedicated recovery environment (like Windows PE) or using specialized, low-level anti-rootkit utilities (e.g., Kaspersky TDSSKiller or GMER) designed to bypass the driver's hooks and remove the malicious `.sys` files from the `System32\\drivers` directory.</li>\n<li><strong>System Re-imaging Recommended:</strong> Because Zacinlo operates at the kernel level and heavily modifies the OS, the most reliable and secure remediation is a complete bare-metal wipe and re-image of the compromised endpoint.</li>\n</ul>",
  "cta": "Published by the SystemHelpdesk team.",
  "aliases": [
    "Adware.Zacinlo",
    "Rootkit.Zacinlo",
    "Win32/Zacinlo.Rootkit"
  ],
  "enrichment_level": "insufficient_information",
  "faq": [],
  "faq_count": 0,
  "mitre_attack": [
    "T1014",
    "T1562.001",
    "T1185",
    "T1553.004"
  ],
  "cisa_advisory": null,
  "last_updated": "2026-07-02T06:54:00Z",
  "type": "Adware / Rootkit",
  "target_industries": [
    "Global / Opportunistic"
  ],
  "motivation": "Opportunistic",
  "threat_actors": [
    "Unknown / Cybercriminal"
  ],
  "target_geographies": [
    "Global"
  ]
}