alert http1 $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Dridex POST CnC Beacon 2"; flow:established,to_server; urilen:1; http.method; content:"POST"; http.header; content:"Content-Type|3a 20|text/css|0d 0a|Accept|3a 20|image/**|0d 0a|"; fast_pattern; http.host; pcre:"/^\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}(?:\x3a\d{1,5})?$/"; http.header_names; content:!"Referer|0d 0a|"; content:"|0d 0a|Host|0d 0a|"; depth:8; http.request_body; byte_extract:1,0,Dridex.Pivot,relative; byte_test:1,!=,Dridex.Pivot,0,relative; byte_test:1,=,Dridex.Pivot,7,relative; reference:md5,b9de687cdae55d3c9fcfe6fc8bcdd28f; classtype:command-and-control; sid:2020301; rev:5; metadata:attack_target Client_Endpoint, created_at 2015_01_23, deployment Perimeter, signature_severity Major, tag c2, updated_at 2024_04_07, mitre_tactic_id TA0010, mitre_tactic_name Exfiltration, mitre_technique_id T1041, mitre_technique_name Exfiltration_Over_C2_Channel;)