This is the list of some of the best free security tools available for various purposes, these tools will allow you to perform tasks like password recovery, penetration testing, vulnerability scanning and secure data wiping.
BackTrack is a free bootable Linux distribution. Its only purpose is to test your network, devices, and systems for security vulnerabilities.
BackTrack is packed with lots of security and hacker tools and is often used by security professionals and hackers.
Wireshark is a must have cross-platform application. It is a network packet capture and analysis program that assists you with your ongoing quest for a trouble-free network.
Wireshark wont prevent network problems, but it does allow you to analyze those problems in real time and possibly avoid failure.
Eraser is an advanced security tool for Windows which allows you to completely remove sensitive data from your hard drive by overwriting it several times with carefully selected patterns.
Sysinternals Suite is a collection of system utilities designed to assist users in diagnosing and troubleshooting Windows applications and services.
The suite includes over seventy utilities aimed to troubleshoot matters related to files and disk management, networking and security issues, as well as process and system information.
TinyWall is a free software to harden and control the advanced firewall built into modern Windows systems.
Tampering protection, blocklists, and temporary firewall rules, among others, add new features to Windows that increase security.
Malwarebytes Anti-Malware application for Windows can detect and remove malware that even the most well known anti-virus and anti-malware applications fail to detect.
SoftPerfect Network Scanner
SoftPerfect Network Scanner is a free multi-threaded IP, NetBIOS and SNMP scanner with a modern interface and many advanced features. It is intended for both system administrators and general users interested in computer security.
The program pings computers, scans for listening TCP/UDP ports and displays which types of resources are shared on the network, including system and hidden ones.
Smoothwall Open Source
Smoothwall is a Firewall, IDS and VPN system for home users and medium size business networks.
IPSecuritas is the most advanced, yet free IPSec client for Mac OS X. It supports virtually every available IPSec compliant firewall, allowing you to connect safely to your office or home network from any location on earth.