I have Cisco ASA-SSM-20 deployed INLINE.
I can cut any traffic without any problems except SSHv2 over HTTP or HTTPS.
Implementation ? - http://dag.wieers.com/howto/ssh-http-tunneling/
Easy, you can make an HTTPS tunnel, then SSH over HTTPS and after that LOCAL PORT FORWARDING so you can get in the company from home ;)
How I can deny souch connection ?? Any signature ? Any ideas or Cisco can't help in this case.