SecTools

QualysGuard : A web-based vulnerability scanner
Delivered as a service over the Web, QualysGuard eliminates the burden of deploying, maintaining, and updating vulnerability management software or implementing ad-hoc security applications. Clients securely access QualysGuard through an easy-to-use Web interface. QualysGuard features 5,000+ unique vulnerability checks, an Inference-based scanning engine, and automated daily updates to the QualysGuard […]

cheops / cheops-ng : Gives a simple interface to many network utilities, maps local or remote networks and identifies OS of machines
Cheops provides the functionality of many network utilities through a comfortable, powerful GUI. It has host/network discovery functionality as well as OS detection of hosts. Cheops-ng has the ability to probe hosts to see […]

ClamAV : A GPL anti-virus toolkit for UNIX
ClamAV is a powerful AntiVirus scanner focused towards integration with mail servers for attachment scanning. It provides a flexible and scalable multi-threaded daemon, a command line scanner, and a tool for automatic updating via the Internet. Clam AntiVirus is based on a shared library distributed with the Clam […]

Sara : Security Auditor’s Research Assistant
SARA is a vulnerability assessment tool that was derived from the infamous SATAN scanner. They try to release updates twice a month and try to leverage other software created by the open source community (such as Nmap and Samba).

Socat : A relay for bidirectional data transfer
A utility similar to the venerable Netcat that works over a number of protocols and through a files, pipes, devices (terminal or modem, etc.), sockets (Unix, IP4, IP6 - raw, UDP, TCP), a client for SOCKS4, proxy CONNECT, or SSL, etc. It provides forking, logging, and dumping, different […]

Whisker/libwhisker : Rain.Forest.Puppy’s CGI vulnerability scanner and library
Libwhisker is a Perl module geared geared towards HTTP testing. It provides functions for testing HTTP servers for many known security holes, particularly the presence of dangerous CGIs. Whisker is a scanner that used libwhisker but is now deprecated in favor of Nikto which also uses libwhisker.

X-scan : A general scanner for scanning network vulnerabilities
A multi-threaded, plug-in-supported vulnerability scanner. X-Scan includes many features, including full NASL support, detecting service types, remote OS type/version detection, weak user/password pairs, and more. You may be able to find newer versions available here if you can deal with most of the page being written in […]

Fragroute/Fragrouter : A network intrusion detection evasion toolkit
Fragrouter is a one-way fragmenting router - IP packets get sent from the attacker to the Fragrouter, which transforms them into a fragmented data stream to forward to the victim. Many network IDS are unable or simply don’t bother to reconstruct a coherent view of the network data […]

Nagios : An open source host, service and network monitoring program
Nagios is a system and network monitoring application. It watches hosts and services that you specify, alerting you when things go bad and when they get better. Some of its many features include monitoring of network services (smtp, pop3, http, nntp, ping, etc.), monitoring of […]

Yersinia : A multi-protocol low-level attack tool
Yersinia is a low-level protocol attack tool useful for penetration testing. It is capable of many diverse attacks over multiple protocols, such as becoming the root role in the Spanning Tree (Spanning Tree Protocol), creating virtual CDP (Cisco Discovery Protocol) neighbors, becoming the active router in a HSRP (Hot […]

OpenBSD : The Proactively Secure Operating System
OpenBSD is one of the only operating systems to treat security as their very highest priority. Even higher than usability in some cases. But their enviable security record speaks for itself. They also focus on stability and fight to obtain documentation for the hardware they wish to support. Perhaps […]

SPIKE Proxy : HTTP Hacking
Spike Proxy is an open source HTTP proxy for finding security flaws in web sites. It is part of the Spike Application Testing Suite and supports automated SQL injection detection, web site crawling, login form brute forcing, overflow detection, and directory traversal detection.

chkrootkit : Locally checks for signs of a rootkit
chkrootkit is a flexible, portable tool that can check for many signs of rootkit intrusion on Unix-based systems. Its features include detecting binary modification, utmp/wtmp/lastlog modifications, promiscuous interfaces, and malicious kernel modules.

Fport : Foundstone’s enhanced netstat
Fport reports all open TCP/IP and UDP ports on the machine you run it on and shows what application opened each port. So it can be used to quickly identify unknown open ports and their associated applications. It only runs on Windows, but many UNIX systems now provided this information via […]

ISS Internet Scanner : Application-level vulnerability assessment
Internet Scanner started off in ‘92 as a tiny open source scanner by Christopher Klaus. Now he has grown ISS into a billion-dollar company with a myriad of security products.

Knoppix : A general-purpose bootable live system on CD or DVD
Knoppix consists of a representative collection of GNU/Linux software, automatic hardware detection, and support for many graphics cards, sound cards, SCSI and USB devices and other peripherals. KNOPPIX can be used as a productive Linux system for the desktop, educational CD, rescue system, or as […]

Nemesis : Packet injection simplified
The Nemesis Project is designed to be a commandline-based, portable human IP stack for UNIX/Linux (and now Windows!). The suite is broken down by protocol, and should allow for useful scripting of injected packet streams from simple shell scripts. If you enjoy Nemesis, you might also want to look at Hping2 […]

Tor : An anonymous Internet communication system
Tor is a toolset for a wide range of organizations and people that want to improve their safety and security on the Internet. Using Tor can help you anonymize web browsing and publishing, instant messaging, irc, ssh, and other applications that use the TCP protocol. Tor also provides a […]

Openbsd PF : The OpenBSD Packet Filter
Like Netfilter and IP Filter on other platforms, OpenBSD users love PF, their firewall tool. It handles network address translation, normalizing TCP/IP traffic, providing bandwidth control, and packet prioritization. It also offers some eccentric features, such as passive OS detection. Coming from the same guys who created OpenBSD, you […]

OSSEC HIDS : An Open Source Host-based Intrusion Detection System
OSSEC HIDS performs log analysis, integrity checking, rootkit detection, time-based alerting and active response. In addition to its IDS functionality, it is commonly used as a SEM/SIM solution. Because of its powerful log analysis engine, ISPs, universities and data centers are running OSSEC HIDS to monitor […]

KisMAC : A A GUI passive wireless stumbler for Mac OS X
This popular stumbler for Mac OS X offers many of the features of its namesake Kismet, though the codebase is entirely different. Unlike console-based Kismet, KisMAC offers a pretty GUI and was around before Kismet was ported to OS X. It also offers mapping, […]

Arpwatch : Keeps track of ethernet/IP address pairings and can detect certain monkey business
Arpwatch is the classic ARP man-in-the-middle attack detector from LBNL’s Network Research Group. It syslogs activity and reports certain changes via email. Arpwatch uses LibPcap to listen for ARP packets on a local ethernet interface.

Ike-scan : VPN detector/scanner
Ike-scan exploits transport characteristics in the Internet Key Exchange (IKE) service, the mechanism used by VPNs to establish a connection between a server and a remote client. It scans IP addresses for VPN servers by sending a specially crafted IKE packet to each host within a network. Most hosts running IKE will […]

RKHunter : An Unix Rootkit Detector
RKHunter is scanning tool that checks for signs of various pieces of nasty software on your system like rootkits, backdoors and local exploits. It runs many tests, including MD5 hash comparisons, default filenames used by rootkits, wrong file permissions for binaries, and suspicious strings in LKM and KLD modules.

Angry IP Scanner : A fast windows IP scanner and port scanner
Angry IP Scanner can perform basic host discovery and port scans on Windows. Its binary file size is very small compared to other scanners and other pieces of information about the target hosts can be extended with a few plugins.