alert tcp $EXTERNAL_NET 1024: -> $HOME_NET any (msg:"ET MALWARE Delf CnC Channel Keepalive Ping"; flow:established,from_server; dsize:22; content:"|12 00 00 00 1c 5e|"; depth:6; classtype:command-and-control; sid:2008010; rev:6; metadata:created_at 2010_07_30, confidence Medium, signature_severity Major, updated_at 2019_07_26;)