ET MALWARE Win32/CryPy Ransomware Encrypting File

alert http $HOME_NET any -> $EXTERNAL_NET any (
    msg:"ET MALWARE Win32/CryPy Ransomware Encrypting File";
    flow:established,to_server;
    http.method;
    content:"GET";
    http.uri;
    content:"/savekey.php?file="; fast_pattern;
    content:"&id="; distance:0;
    pcre:"/\/savekey\.php\?file=(?:[A-Za-z0-9+/]{4})*(?:[A-Za-z0-9+/]{2}==|[A-Za-z0-9+/]{3}=|[A-Za-z0-9+/]{4})&id=(?:[A-Za-z0-9+/]{4})*(?:[A-Za-z0-9+/]{2}==|[A-Za-z0-9+/]{3}=|[A-Za-z0-9+/]{4})$/i";
    http.user_agent;
    content:"Python-urllib"; startswith;
    http.header_names;
    content:!"Accept";
    content:!"Referer|0d 0a|";
    reference:md5,8bd7cd1eee4594ad4886ac3f1a05273b;
    reference:url,nakedsecurity.sophos.com/2016/10/18/data-stealing-crpy-ransomware/;
    classtype:trojan-activity;
    sid:2023346; rev:3;
    metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2016_10_18, deployment Perimeter, malware_family Ransomware, malware_family CryPy, signature_severity Major, tag Ransomware, updated_at 2020_07_31, mitre_tactic_id TA0040, mitre_tactic_name Impact, mitre_technique_id T1486, mitre_technique_name Data_Encrypted_for_Impact;
)