alert tcp $HOME_NET !$HTTP_PORTS -> $EXTERNAL_NET 1337 (msg:"ET MALWARE Win32.SkSocket C&C Connection"; flow:established,to_server; flags:PA,12; dsize:1; content:"|04|"; classtype:command-and-control; sid:2007585; rev:4; metadata:created_at 2010_07_30, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2019_07_26;)