We're very impressed by the collective smarts of the security community and we highly recommend reading the whole list and investigating any tools you are unfamiliar with. Click any tool name for more details on that particular application, including the chance to read (and write) reviews. Many site elements are explained by tool tips if you hover your mouse over them. Enjoy!
A file and directory integrity checker. Tripwire is a tool that aids system administrators and users in monitoring a designated set of files for any changes. Used with system files on a regular (e.g., daily) basis, Tripwire can notify system administrators of corrupted or tampered files, so damage control measures can be taken in a timely manner. Traditionally an open souce tool, Tripwire Corp is now focused on their commercial enterprise configuration control offerings. An open source Linux version can still be found at SourceForge. UNIX users may also want to consider AIDE, which has been designed to be a free Tripwire replacement. Or you may wish to investigate Radmind, rkhunter, or chkrootkit. Windows users may like RootkitRevealer from Sysinternals.
Review this tool.
NetScanTools is a collection of over 40 network utilities for Windows, designed with an easy user interface in mind. It includes DNS tools, a ping and port scanner, traceroute, and other utilities. It comes in bundles with more or fewer tools based on the price.
Read 3 reviews.
Latest release: version 11.30 on May 8, 2012 (4 years, 11 months ago).
DumpSec is a security auditing program for Microsoft Windows NT/XP/200x. It dumps the permissions (DACLs) and audit settings (SACLs) for the file system, registry, printers and shares in a concise, readable format, so that holes in system security are readily apparent. DumpSec also dumps user, group and replication information.
Read 2 reviews.
Latest release: version 2.8.6 on June 3, 2010 (6 years, 11 months ago).
SAINT is a commercial vulnerability assessment tool. Like Nessus, it used to be free and open source but is now a commercial product. Unlike Nexpose, and QualysGuard, SAINT runs on Linux and Mac OS X. In fact, SAINT is one of the few scanner vendors that don't support (run on) Windows at all.
Read 5 reviews.
Latest release: version 7.13 on May 18, 2012 (4 years, 11 months ago).
ArcSight provides a suite of tools for SIEM—security information and event management. The best-known seems to be ArcSight Enterprise Security Manager (ESM), described as the "brain" of the SIEM platform. It is a log analyzer and correlation engine designed to sift out important network events. The ESM itself is a standalone appliance, and the management programs run on Linux, Windows, AIX, and Solaris. For open-source alternatives see OSSEC HIDS and OSSIM.
Read 2 reviews.
EnCase is a suite of computer forensics software, commonly used by law enforcement. Its wide use has made it a de-facto standard in forensics. It is made to collect data from a computer in a forensically sound manner (employing checksums to help detect tampering).
Read 2 reviews.
Latest release: version 7.10.05 on March 18, 2015 (2 years, 1 month ago).