alert tcp $EXTERNAL_NET any -> $HOME_NET 22 (msg:"GPL SCAN ssh-research-scanner"; flow:to_server,established; content:"|00 00 00|`|00 00 00 00 00 00 00 00 01 00 00 00|"; classtype:attempted-recon; sid:2100617; rev:5; metadata:created_at 2010_09_23, confidence Medium, signature_severity Informational, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2019_07_26;)