alert tcp any !$SSH_PORTS -> any any (msg:"ET POLICY SSH Server Banner Detected on Unusual Port"; flowbits:noalert; flow:from_server,established; content:"SSH-"; offset:0; depth:4; byte_test:1,>,48,0,relative; byte_test:1,<,51,0,relative; byte_test:1,=,46,1,relative; flowbits:set,ET.is_ssh_server_banner; classtype:misc-activity; sid:2001979; rev:8; metadata:created_at 2010_07_30, confidence High, signature_severity Informational, updated_at 2019_07_26;)