Hi,
Sep 26 20:30:05 NAME telnetd[30969]: ttloop: read: Broken pipe
This would most likely be Active Monitor and the chance you've been hacked is always there, but based on the above message I have no way of saying. Do you get this message every 15 minutes?
Gerald was right: ditch telnet, get openssh. If you would rather not rely on Sun/Cobalt to keep making up-to-date packages, head on over to http://www.openssh.com, click Linux (which will lead you to the 'portable' section) and then find a suitable mirror. Get the RedHat 6.2 RPMS and do subscribe to the announce list.
HTH... Nico