ET MALWARE Win32/CHIP Ransomware CnC Checkin

alert http $HOME_NET any -> $EXTERNAL_NET any (
    msg:"ET MALWARE Win32/CHIP Ransomware CnC Checkin";
    flow:established,to_server;
    http.method;
    content:"POST";
    http.uri;
    content:".php";
    http.host;
    pcre:"/^\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}(?:\x3a)?/";
    http.request_body;
    content:"-----BEGIN CERTIFICATE-----"; depth:27; fast_pattern;
    content:"-----END CERTIFICATE-----"; distance:0;
    http.content_type;
    content:"application/x-www-form-urlencoded"; startswith;
    http.header_names;
    content:!"Accept";
    content:!"Referer|0d 0a|";
    reference:md5,18189daa96e711777158d7cb599c13b1;
    reference:url,malware-traffic-analysis.net/2016/11/17/index.html;
    classtype:command-and-control;
    sid:2023534; rev:4;
    metadata:attack_target Client_Endpoint, created_at 2016_03_07, deployment Perimeter, malware_family Win32_CHIP, signature_severity Major, tag Ransomware, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2020_08_03, mitre_tactic_id TA0040, mitre_tactic_name Impact, mitre_technique_id T1486, mitre_technique_name Data_Encrypted_for_Impact;
)