These programs can help you block or monitor the ports on your computer to determine if a malicious hacker is trying to access or probe your computer.


  • Anti-Hack Monitors your open ports to detect unauthorized access attempts. Shareware. (

  • AntiSniff Detects port sniffing on a network. Freeware. (

  • Attacker Monitors your ports for suspicious behavior and notifies you when someone tries to connect to your computer through a Trojan. Freeware. (

  • BlackICE Defender Intrusion detection and a personal firewall. Demoware. (

  • Jammer Monitors ports on your computer to detect attempted break-ins. Shareware. (

  • McAfee Personal Firewall Secures your computer from hackers. Trialware. (

  • Netmon Monitors your ports for suspicious behavior and detects the more common Trojan horses. Freeware. (

  • NukeNabber Monitors your computer ports to alert you when someone may be trying to access your computer using a Trojan horse. Freeware. (

  • Port Blocker Blocks open ports on your computer to prevent them from being used by hackers or Trojan horses. Freeware. (No installation support.)

  • ProtectX Monitors your ports to detect and remove any Trojan horses that could be used to access your computer. Shareware. (

  • Rainbow Diamond Intrusion Detection Detects suspicious activity through your ports. Demoware. (

  • SuperScan Port scanner that probes your computer to detect any open ports that could be vulnerable to a remote attack, such as through a Trojan horse. Freeware. (

  • ZoneAlarm Firewall that protects your computer from port scanners and remote access Trojans. Freeware. (


  • TrashScan Monitors the ports on your Macintosh to make sure an intruder isn't secretly accessing your computer over a network or the Internet. Freeware. (