alert tcp $EXTERNAL_NET any -> $HOME_NET 22 (msg:"ET EXPLOIT Catalyst SSH protocol mismatch"; flow:to_server,established; content:"|61 25 61 25 61 25 61 25 61 25 61 25 61 25|"; reference:url,www.cisco.com/warp/public/707/catalyst-ssh-protocolmismatch-pub.shtml; classtype:attempted-dos; sid:2000007; rev:7; metadata:created_at 2010_07_30, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2019_07_26;)