It is on the order of random-typewriter monkeys producing Hamlet that this particular issue could happen from a bad RPM -- but it is *quite* likely that it could happen if your system were hacked and someone clumbsily installed a trojaned sshd. What happens if you run "rpm -V openssh"?
When I run that I get no output. It just returns to the prompt. This is the same on a system that works and a system that doesnt.
And, uh, I'd also run chkrootkit.
I've run chkrootkit on 3 systems. All report "nothing found" or "not detected." netstat -pant only shows connections to port 22 from legit places. Thanks, Mike