alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE PlugX CnC Beacon"; flow:established,to_server; http.method; content:"POST"; http.uri; content:"?id="; fast_pattern; pcre:"/\?id=[a-f0-9]{8}$/"; http.header; header_lowercase; content:"accept|3a 20 2a 2f 2a 0d 0a|"; pcre:"/^[^\x3a]+\x3a\x20\d+\r\n[^\x3a]+\x3a\x20\d+\r\n[^\x3a]+\x3a\x20\d+\r\n[^\x3a]+\x3a\x20\d+\r\nUser-Agent\x3a/Ri"; http.header_names; to_lowercase; content:!"|0d 0a|accept-"; content:!"|0d 0a|referer|0d 0a|"; reference:md5,076ae76dcd0946ff913a9ce033e0ca55; classtype:command-and-control; sid:2036858; rev:5; metadata:attack_target Client_Endpoint, created_at 2015_08_20, deployment Perimeter, performance_impact Significant, confidence Medium, signature_severity Major, tag c2, updated_at 2024_04_21, mitre_tactic_id TA0010, mitre_tactic_name Exfiltration, mitre_technique_id T1041, mitre_technique_name Exfiltration_Over_C2_Channel;)