Cat Guardian

Cat Guardian is a free, open-source real-time security suite for Windows. It combines a ClamAV-based antivirus engine, deep integrity monitoring of system files and the registry, Windows Firewall management with Threat Intelligence feeds, and a broad set of proactive protection modules against ransomware, cryptojackers, credential stealers, keyloggers, screen lockers and other modern threats.

Key Features

• Real-time antivirus protection powered by the ClamAV engine with automatic signature database updates and an instant malware hash index (built from ClamAV signature databases) for immediate detection
• File Inspector: integrity control of critical Windows system files and registry keys, with decoy (honeypot) files that detect unauthorized access attempts
• Windows Firewall management backed by Threat Intelligence databases (CINS Army List, ET Block List)
• Ransomware protection with behavioral analysis and decoy files
• Anti-miner (cryptojacking protection) with threat domain lists and DNS-based blocking
• Anti-stealer protection for browser-stored passwords and Windows system credentials
• Anti-spyware protection against keyloggers and screen-capture tools
• Screen-locker protection with Winlogon/Userinit integrity checks
• AMSI script inspection for PowerShell, Office VBA, cscript/wscript and other script hosts
• Hidden WMI handler protection (event subscriptions, XSL filters)
• LOLBins and anomalous parent-child process detection
• DLL hijacking and fileless attack detection
• AppContainer sandbox for running high-risk executables in isolation
• Fast entropy analysis to detect packed and encrypted malware
• Clipboard protection against crypto-clipper attacks
• Privacy Shield: camera and microphone access control
• Spyware browser extension watchdog
• Autostart control and shortcut hijack protection
• Port listener and network heuristic monitoring
• Reputation-based pre-scan scoring (Pre-Scan) with digital signature verification
• Quarantine, on-demand and scheduled scanning
• First-run wizard, multiple UI themes, Russian and English localization
• Self-defense: file locking, registry protection, anti-kill filter