Verify that sshd is not infected :
strings /usr/sbin/sshd | grep %s:%s -A2 -B2 |head -3
If this outputs any file name, then check the filename if it has any passwords on that file.

Verify that ssh, sftp etc.. are not infected :
rpm -Vv openssh openssh-server openssh-clients | egrep -v '^\.\.\.\.\.\.\.' | egrep -v sshd_config
There shouldnot be any output for the above command.

Verify if ssh supports TCP Wrappers

strings $(which sshd)| grep libwrap