alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Malicious Office Doc CnC Beacon"; flow:established,to_server; http.method; content:"GET"; http.uri; content:"/im"; content:"g"; distance:0; content:".php?id="; fast_pattern; pcre:"/\/im(?:age|g)\.php\?id=\d+$/"; http.user_agent; content:"MSOffice"; content:!"Outlook"; http.header_names; to_lowercase; content:!"|0d 0a|referer|0d 0a|"; reference:md5,27cd0a3db18fbb6d316fb4542c3a51f3; classtype:command-and-control; sid:2020860; rev:8; metadata:attack_target Client_Endpoint, created_at 2015_04_08, deployment Perimeter, signature_severity Major, tag c2, updated_at 2024_04_20, mitre_tactic_id TA0010, mitre_tactic_name Exfiltration, mitre_technique_id T1041, mitre_technique_name Exfiltration_Over_C2_Channel;)