alert tcp $HOME_NET any -> $EXTERNAL_NET 1024: (msg:"ET DELETED Delf CnC Channel Checkin Replies"; flowbits:isset,ET.unk.2; flow:established,to_server; dsize:<20; content:"|09 00 00 00|"; depth:4; classtype:command-and-control; sid:2008008; rev:6; metadata:created_at 2010_07_30, signature_severity Unknown, updated_at 2019_07_26;)