The sys admin's daily grind: Whowatch et al.

On Patrol

Article from Issue 155/2013
Author(s):

For no particular reason, Charly occasionally patrols his server farm and hunts down attackers. He has put together a neat toolbox for this job.

Every server with an IP address on the Internet will receive uninvited visits at some point. The usual scans and scripted carpet bombing simply bounce off my machines thanks to clever firewalling, port knocking [1], and additional tools like Fail2ban [2]. To keep attackers from working around my defenses, I use two rootkit hunters: Rootkit Hunter [3] and Chkrootkit [4]. The latter, unfortunately, accuses my DHCP server of packet sniffing:

eth0: PACKET SNIFFER(/usr/sbin/dhcpd[28382])

This result is a known false positive, which I ignore. As an interim report, I can say that my varmint hunters have not seen any prey thus far.

[...]

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