ET MALWARE [eSentire] Win32/GandCrab v4/5 Ransomware CnC Activity

alert http $HOME_NET any -> $EXTERNAL_NET any (
    msg:"ET MALWARE [eSentire] Win32/GandCrab v4/5 Ransomware CnC Activity";
    flow:established,to_server;
    threshold:type limit, count 1, seconds 60, track by_src;
    http.method;
    content:"POST";
    http.uri;
    pcre:"/\.(?:bmp|png|gif|jpg)$/";
    http.user_agent;
    content:"Mozilla/5.0 (Windows NT 6.1|3b 20|WOW64";
    http.request_body;
    content:"wfKD6iudumBkmp"; depth:14; fast_pattern;
    pcre:"/^(?:[A-Za-z0-9+/]{4})*(?:[A-Za-z0-9+/]{2}==|[A-Za-z0-9+/]{3}=|[A-Za-z0-9+/]{4})$/si";
    http.content_type;
    content:"multipart/form-data"; startswith;
    http.header_names;
    content:!"Referer";
    content:!"Accept";
    classtype:command-and-control;
    sid:2025638; rev:4;
    metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2018_07_04, deployment Perimeter, malware_family GandCrab, confidence High, signature_severity Major, tag Ransomware, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2020_08_25, mitre_tactic_id TA0040, mitre_tactic_name Impact, mitre_technique_id T1486, mitre_technique_name Data_Encrypted_for_Impact;
)