ET MALWARE W32/Siggen.Dropper CnC Beacon

alert http $HOME_NET any -> $EXTERNAL_NET any (
    msg:"ET MALWARE W32/Siggen.Dropper CnC Beacon";
    flow:established,to_server;
    http.uri;
    content:".jpg?log="; fast_pattern;
    content:"&ts="; offset:11;
    content:"&act="; distance:0;
    http.header;
    content:"client|3a 20|";
    http.header_names;
    content:!"Referer|0d 0a|";
    reference:md5,ee363de2168aab353c829434189350e4;
    classtype:command-and-control;
    sid:2019515; rev:4;
    metadata:attack_target Client_Endpoint, created_at 2014_10_27, deployment Perimeter, signature_severity Major, tag c2, updated_at 2020_09_25, mitre_tactic_id TA0010, mitre_tactic_name Exfiltration, mitre_technique_id T1041, mitre_technique_name Exfiltration_Over_C2_Channel;
)