Tor is a network of virtual tunnels that allows people and groups to improve their privacy and security on the Internet. It also enables software developers to create new communication tools with built-in privacy features. It provides the foundation for a range of applications that allow organizations and individuals to share information over public networks without compromising their privacy. Individuals can use it to keep remote Websites from tracking them and their family members. They can also use it to connect to resources such as news sites or instant messaging services that are blocked by their local Internet service providers (ISPs).
The Mandos system allows computers to have encrypted root file systems and at the same time be capable of remote or unattended reboots. The computers run a small client program in the initial RAM disk environment which will communicate with a server over a network. All network communication is encrypted using TLS. The clients are identified by the server using an OpenPGP key that is unique to each client. The server sends the clients an encrypted password. The encrypted password is decrypted by the clients using the same OpenPGP key, and the password is then used to unlock the root file system.
Endian Firewall is an all-in-on Linux security distribution that turns any system into a full-featured security appliance. It features a stateful packet inspection firewall, application-level proxies for various protocols (HTTP, POP3, SMTP), anti-virus support, virus and spam filtering for email traffic (POP and SMTP), content filtering of Web traffic, and a "hassle free" VPN system based on OpenVPN.
DansGuardian is a Web content filtering proxy that uses Squid to do all the fetching. It filters using multiple methods including, but not limited to, phrase matching, file extension matching, MIME type matching, PICS filtering, and URL/domain blocking. It has the ability to switch off filtering by certain criteria including username, domain name, source IP, etc. The configurable logging produces a log in an easy to read format. It has the option to only log text-based pages, thus significantly reducing redundant information (such as every image on a page).
GNUnet is a peer-to-peer framework with focus on providing security. All peer-to-peer messages in the network are confidential and authenticated. The framework provides a transport abstraction layer and can currently encapsulate the network traffic in UDP, TCP, HTTP, HTTPS, or direct 802.11 (WLAN). GNUnet supports accounting to provide contributing nodes with better service. The services built on top of the framework include anonymous file sharing and a virtual network providing IPv4-IPv6 transition via protocol translation over the P2P network.
chkrootkit is a tool to locally check for signs of a rootkit. It contains a chkrootkit: shell script that checks system binaries for rootkit modification. The following tests are made: aliens, asp, bindshell, lkm, rexedcs, sniffer, wted, z2, amd, basename, biff, chfn, chsh, cron, date, du, dirname, echo, egrep, env, find, fingerd, gpm, grep, hdparm, su, ifconfig, inetd, inetdconf, identd, killall, login, ls, mail, mingetty, netstat, named, passwd, pidof, pop2, pop3, ps, pstree, rpcinfo, rlogind, rshd, slogin, sendmail, sshd, syslogd, tar, tcpd, top, telnetd, timed, traceroute, and write. ifpromisc.c checks whether the interface is in promiscuous mode, chklastlog.c checks for lastlog deletions, chkwtmp.c checks for wtmp deletions, check_wtmpx.c checks for wtmpx deletions (Solaris only), and chkproc.c checks for signs of LKM trojans.
Firewall Builder consists of a GUI and set of policy compilers for various firewall platforms. It helps users maintain a database of objects and allows policy editing using simple drag-and-drop operations. The GUI and policy compilers are completely independent, which provides for a consistent abstract model and the same GUI for different firewall platforms. It currently supports iptables, ipfilter, ipfw, OpenBSD pf, Cisco PIX and FWSM, and Cisco routers access lists.
aircrack-ng is a set of tools for auditing wireless networks. It's an enhanced/reborn version of aircrack. It consists of airodump (an 802.11 packet capture program), aireplay (an 802.11 packet injection program), aircrack (static WEP and WPA-PSK cracking), airdecap (decrypts WEP/WPA capture files), and some tools to handle capture files (merge, convert, etc.).