Tony Arnold wrote: > [...] > Having said, that Linux is not immune from the hackers. My experience is > that most incidents with Linux machines have been down to week or > default passwords. Hackers can then get in and use the machine to scan > other machines for weaknesses. My guess is if you put a machine on the > netork with an ssh daemon running and a user name of david and password > of david (for example), then it will be compromised within 24 hours or > less. (I know someone who did exactly this).
Hello, Tony. I second that: We got hit because a user with a dictionary name set a password of 12345 ... You can slow down 'brute-force' attacks using IP-tables with, for example, "fail2ban", which is in the Ubuntu repo's. This 'bans' an IP after a configurable number of failed login attempts. However, it's not just SSH that you have to worry about: One of my servers was recently caught sending 100,000 SPAM emails because it had been compromised using a PHP exploit via port 80. I've previously used "Nikto" to check web servers for vulnerabilities: http://www.cirt.net/nikto2 I've used "nessus": http://www.nessus.org/nessus/ In the good old days, "nessus" was GPL. Unfortunately, "nessus" is no longer FLOSS and requires a paid for subscription for 'professional' use. However, there is now a FLOSS fork of the previously GPL "nessus" code called OpenVAS: http://www.openvas.org/ I've been trying this out recently, and it looks very good! Bye, Tony. -- Dr. A.J.Travis, University of Aberdeen, Rowett Institute of Nutrition and Health, Greenburn Road, Bucksburn, Aberdeen AB21 9SB, Scotland, UK tel +44(0)1224 712751, fax +44(0)1224 716687, http://www.rowett.ac.uk mailto:a.tra...@abdn.ac.uk, http://bioinformatics.rri.sari.ac.uk/~ajt -- ubuntu-uk@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-uk https://wiki.ubuntu.com/UKTeam/