ET MALWARE DonotGroup Pult Downloader Activity (POST)

alert http $HOME_NET any -> $EXTERNAL_NET any (
    msg:"ET MALWARE DonotGroup Pult Downloader Activity (POST)";
    flow:established,to_server;
    urilen:8<>25;
    http.method;
    content:"POST";
    http.uri;
    content:!".php";
    http.content_type;
    content:"application/x-www-form-urlencoded"; bsize:33;
    http.request_body;
    content:"batac="; startswith; fast_pattern;
    pcre:"/^(?:[A-Za-z0-9+/]{4})*(?:[A-Za-z0-9+/]{2}==|[A-Za-z0-9+/]{3}=|[A-Za-z0-9+/]{4})$/R";
    http.user_agent;
    content:!"Linux|3b|";
    content:!"iPhone|3b|";
    http.header_names;
    content:"|0d 0a|Content-Type|0d 0a|User-Agent|0d 0a|Host|0d 0a|Content-Length|0d 0a|Cache-Control|0d 0a 0d 0a|";
    content:!"Referer";
    reference:md5,765c01936caae2ba1b1b50ae1ed76cc0;
    classtype:trojan-activity;
    sid:2035534; rev:1;
    metadata:attack_target Client_Endpoint, created_at 2022_03_18, deployment Perimeter, deployment SSLDecrypt, malware_family DonotGroup, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2022_03_18;
)