ET MALWARE Win32/MereTam.A Ransomware CnC Checkin

alert http $HOME_NET any -> $EXTERNAL_NET any (
    msg:"ET MALWARE Win32/MereTam.A Ransomware CnC Checkin";
    flow:established,to_server;
    http.method;
    content:"POST";
    http.uri;
    content:"/?submit";
    http.request_body;
    content:"session-id="; depth:11;
    pcre:"/^[a-f0-9]{8}-[a-f0-9]{4}-[a-f0-9]{4}-[a-f0-9]{4}-[a-f0-9]{12}/Rs";
    content:"&id="; distance:0; within:4;
    content:"&country=";
    content:"&operatingSystem=";
    content:"&cpuModel=";
    content:"&machineName=";
    content:"&randomAccessMemory="; fast_pattern;
    http.header_names;
    content:!"Accept";
    content:!"Cache-";
    content:!"Referer";
    content:!"User-Agent";
    reference:md5,b306115dc9c137b0fa455a9ce1708917;
    classtype:trojan-activity;
    sid:2032420; rev:1;
    metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2021_04_05, deployment Perimeter, malware_family Win32_MereTam_A, confidence High, signature_severity Major, tag Ransomware, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2021_04_05, mitre_tactic_id TA0040, mitre_tactic_name Impact, mitre_technique_id T1486, mitre_technique_name Data_Encrypted_for_Impact;
)