Free security tools for Windows and Linux hosts: ClamAV antivirus, GlassWire firewall monitor, OSArmor and Maltrail threat detection.
ClamAV is Cisco Talos’ free, open-source antivirus engine. It scans files, uploads and email on Linux, Windows and macOS from the command line or through the clamd daemon, with signature updates via freshclam. It is a server scanner, not a desktop suite.
Network monitor and firewall for Windows 10 and 11 (x64, ARM64): live traffic graph, per-app data usage and alerts on new connections. Shareware (conditionally free): the free tier keeps 24 hours of history; firewall control needs Premium.
OSArmor is a Windows hardening layer from NoVirusThanks that blocks suspicious process behaviour: Office apps spawning PowerShell, script-host abuse, shadow-copy deletion and USB malware. It runs alongside your antivirus. Shareware (conditionally free).
Maltrail is a free, open-source (MIT) malicious traffic detection system. A Rust sensor matches traffic against public blacklists and heuristics and reports hits to a web dashboard. Runs on Linux, BSD, macOS and Windows 10+.
