alert http $EXTERNAL_NET 80 -> $HOME_NET any (msg:"ET MALWARE CommentCrew Possible APT c2 communications sleep"; flow:established,to_client; file_data; content:"<!-- dWdzMTA= -->"; classtype:targeted-activity; sid:2016478; rev:3; metadata:attack_target Client_Endpoint, created_at 2013_02_22, deployment Perimeter, confidence Medium, signature_severity Major, tag c2, updated_at 2019_07_26, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1071, mitre_technique_name Application_Layer_Protocol;)