ET MALWARE Win32/Emotet CnC Activity M12 (POST)

alert http $HOME_NET any -> $EXTERNAL_NET [80,443,4143,7080,8080] (
    msg:"ET MALWARE Win32/Emotet CnC Activity M12 (POST)";
    flow:established,to_server;
    http.method;
    content:"POST";
    http.uri;
    content:!".";
    content:!"&";
    content:!"-";
    content:!"?";
    content:"/"; endswith;
    http.header_names;
    content:"|0d 0a|Connection|0d 0a|Content-Type|0d 0a|Content-Length|0d 0a|Host|0d 0a 0d 0a|"; startswith; fast_pattern;
    http.content_type;
    content:"application/x-www-form-urlencoded"; bsize:33;
    http.request_body;
    content:"="; depth:17;
    content:!"rtype="; depth:6;
    pcre:"/^[A-Za-z]{2,16}=(?:[A-Za-z0-9+/]{4})*(?:[A-Za-z0-9+/]{2}==|[A-Za-z0-9+/]{3}=|[A-Za-z0-9+/]{4})/";
    content:"&"; within:4;
    http.content_len;
    byte_test:0,<,2048,0,string,dec;
    classtype:trojan-activity;
    sid:2043308; rev:7;
    metadata:attack_target Client_Endpoint, created_at 2023_01_17, deployment Perimeter, deployment SSLDecrypt, malware_family Emotet, performance_impact Low, confidence Medium, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2023_03_16, reviewed_at 2023_11_14;
    target:src_ip;
)