alert tcp $HOME_NET any -> $EXTERNAL_NET 1024: (msg:"ET MALWARE Delf CnC Channel Keepalive Pong"; flow:established,to_server; dsize:<40; content:"|20 00 00 00 f8 4d b2 77|"; depth:8; classtype:command-and-control; sid:2008009; rev:5; metadata:created_at 2010_07_30, confidence Medium, signature_severity Major, updated_at 2019_07_26;)