December 29, 2000, 2:00 PM — Last week, I spent most of my time installing Linux and a few white hat applications from hacker Web sites: Firewalk, Nmap, Sniffit, Swatch and Tripwire. This week, I've had a bit of a chance to play around with them.
This "white hat" nomenclature confused me when I first heard it. White hat is a fairly common term for people who hack legitimately - security staff, researchers and so on. By contrast, black hat hackers hack maliciously. Basically, white hats are the good guys; black hats are the bad guys. Gray hats are somewhere between the two, and nobody knows where Red Hat Linux fits in with all this.
I'm told the terms come from the early Western movies. Because the movies were filmed in black and white, the chase scenes tended to get a bit confusing, until someone decided to give the good guys white hats and the bad guys black hats. Anyway, back to Linux.
Frills and Thrills
Nmap impressed me. It's simple, it's powerful, and it does exactly what it says it does: It maps your network. The author, who goes only by the name Fyodor, even includes a short but well-written HTML manual in a choice of five languages. The program is freeware, so you've got to admire the amount of work that he's put into it.
Nmap runs ping sweeps to find out what machines are connected to your local network, a port scan to find out what services each machine is running and TCP/IP fingerprinting to find out what operating system each is running. The result is a log file giving you a reasonably complete list of what's on your network and what it's doing. That's useful information both for a security manager and any hacker.