ET MALWARE PseudoManuscrypt Activity (POST)

alert http $HOME_NET any -> $EXTERNAL_NET any (
    msg:"ET MALWARE PseudoManuscrypt Activity (POST)";
    flow:established,to_server;
    http.method;
    content:"POST";
    http.uri;
    content:".php"; endswith;
    http.request_body;
    content:"p="; startswith; fast_pattern;
    pcre:"/^(?:[A-Za-z0-9@+/]{4})*(?:[A-Za-z0-9@+/]{2}==|[A-Za-z0-9@+/]{3}=|[A-Za-z0-9@+/]{4})$/R";
    http.content_type;
    content:"application/x-www-form-urlencoded"; bsize:33;
    http.header_names;
    content:"|0d 0a|Accept|0d 0a|Content-Type|0d 0a|"; startswith;
    content:!"Referer|0d 0a|";
    reference:md5,b9363486500e209c05f97330226bbf8a;
    classtype:trojan-activity;
    sid:2043997; rev:1;
    metadata:attack_target Client_Endpoint, created_at 2023_01_26, deployment Perimeter, deployment SSLDecrypt, performance_impact Moderate, confidence Medium, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2023_01_26;
    target:src_ip;
)