alert tcp $EXTERNAL_NET any -> $HOME_NET any (msg:"ET MALWARE Bifrose Response from Controller"; flow:established,from_server; dsize:9; content:"|05 00 00 00 BC|"; depth:5; content:"|CC|"; distance:3; within:4; classtype:trojan-activity; sid:2008274; rev:4; metadata:created_at 2010_07_30, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2019_07_26;)