Nmap (“Network Mapper”) is a free and open source (license) utility for network discovery and security auditing. Nmap uses raw IP packets in novel ways to determine what hosts are available on the network, what services (application name and version) those hosts are offering, what operating systems (and OS versions) they are running, what type of packet filters/firewalls are in use, and dozens of other characteristics. Nmap homepage.
Wireshark is a network protocol analyzer. It lets you capture and interactively browse the traffic running on a computer network. Wireshark homepage.
3. Metasploit Community edition
Metasploit Community Edition simplifies network discovery and vulnerability verification for specific exploits, increasing the effectiveness of vulnerability scanners. This helps prioritize remediation and eliminate false positives, providing true security risk intelligence. Metasploit community edition homepage.
Nikto is an Open Source (GPL) web server scanner which performs comprehensive tests against web servers for multiple items, including over 6400 potentially dangerous files/CGIs, checks for outdated versions of over 1200 servers, and version specific problems on over 270 servers. It also checks for server configuration items such as the presence of multiple index files, HTTP server options, and will attempt to identify installed web servers and software. Nikto2 homepage.
5. John the Ripper
John the Ripper is a fast password cracker, currently available for many flavors of Unix, Windows, DOS, BeOS, and OpenVMS. Its primary purpose is to detect weak Unix passwords. Besides several crypt(3) password hash types most commonly found on various Unix systems, supported out of the box are Windows LM hashes, plus lots of other hashes and ciphers in the community-enhanced version. John the Ripper homepage.
Ettercap is a comprehensive suite for man in the middle attacks. It features sniffing of live connections, content filtering on the fly and many other interesting tricks. It supports active and passive dissection of many protocols and includes many features for network and host analysis. ettercap homepage.
7. NexPose Community edition
The Nexpose Community Edition is a free, single-user vulnerability management solution. Nexpose Community Edition is powered by the same scan engine as Nexpose Enterprise and offers many of the same features. Nexpose homepage.
Ncat is a feature-packed networking utility which reads and writes data across networks from the command line. Ncat was written for the Nmap Project as a much-improved reimplementation of the venerable Netcat. It uses both TCP and UDP for communication and is designed to be a reliable back-end tool to instantly provide network connectivity to other applications and users. Ncat will not only work with IPv4 and IPv6 but provides the user with a virtually limitless number of potential uses. ncat homepage.
Kismet is an 802.11 layer2 wireless network detector, sniffer, and intrusion detection system. Kismet will work with any wireless card which supports raw monitoring (rfmon) mode, and (with appropriate hardware) can sniff 802.11b, 802.11a, 802.11g, and 802.11n traffic. Kismet also supports plugins which allow sniffing other media such as DECT. kismet homepage.
w3af is a Web Application Attack and Audit Framework. The project’s goal is to create a framework to find and exploit web application vulnerabilities that is easy to use and extend. w3af homepage.
hping is a command-line oriented TCP/IP packet assembler/analyzer. The interface is inspired to the ping(8) unix command, but hping isn’t only able to send ICMP echo requests. It supports TCP, UDP, ICMP and RAW-IP protocols, has a traceroute mode, the ability to send files between a covered channel, and many other features. hping homepage.
Burp Suite is an integrated platform for performing security testing of web applications. Its various tools work seamlessly together to support the entire testing process, from initial mapping and analysis of an application’s attack surface, through to finding and exploiting security vulnerabilities. BurpSuite homepage.
A very fast network logon cracker which support many different services. hydra homepage.
sqlmap is an open source penetration testing tool that automates the process of detecting and exploiting SQL injection flaws and taking over of database servers. It comes with a powerful detection engine, many niche features for the ultimate penetration tester and a broad range of switches lasting from database fingerprinting, over data fetching from the database, to accessing the underlying file system and executing commands on the operating system via out-of-band connections. sqlmap homepage.
WebScarab has a large amount of functionality, and as such can be quite intimidating to the new user. But, for the simplest case, intercepting and modifying requests and responses between a browser and HTTP/S server, there is not a lot that needs to be learned. WebScarab homepage.