Many of us will remember the storm over the 1995 release of this useful tool by Wietse Venema and Dan Farmer. SATAN's full name is Security Administrator's Tool for Analysing Networks, which succinctly describes what it does - inspect a network for known security weaknesses and report upon them. These vulnerabilities are reputedly widely known in cracking circles and ought to be known to system administrators. Like any sharp tool, it can be abused. Users should bear in mind the concluding words in SAMBA's README file - SATAN was written to improve Internet security. Don't put our work to shame.

This short, well-written book appears to be aimed at people who are relative novices to network security and should be useful to them. In its 112 pages it:

• Contains a foreword from Wietse Venema.
• Summarises the basics of network security.
• Explains how to obtain and build SATAN. Be aware that SATAN's primary home has moved from the address given. Check outftp://ftp.porcupine.org/pub/security/index.html.
• Describes the process of performing a security audit, including the importance of not probing outside ones own network without permission, which is often interpreted as an attack.
• Explains:
• why the weaknesses SANTA searches for are security problems and ways of plugging the holes.
• How to modify and extend SATAN.
• How to detect if somebody is running SATAN against your machines, and what to do about it.
• Why just getting a clean report doesn't mean that your network is secure and outlines what you should start thinking about next.
• Gives some useful references to other material.