ET MALWARE TA471 Malicious AutoIT File Upload

alert http $HOME_NET any -> $EXTERNAL_NET any (
    msg:"ET MALWARE TA471 Malicious AutoIT File Upload";
    flow:established,to_server;
    http.method;
    content:"POST";
    http.uri;
    content:"/upld/"; startswith;
    http.content_type;
    content:"multipart/form-data|3b| boundary=----WebKitFormBoundary"; startswith;
    http.user_agent;
    content:"Mozilla/4.0 (compatible|3b 20|Win32|3b 20|WinHttp.WinHttpRequest.5)"; bsize:57; fast_pattern;
    http.header_names;
    content:!"Referer";
    content:"|0d 0a|Connection|0d 0a|"; depth:14;
    content:!"Accept-Enc";
    reference:md5,75d6f57cfba0ebc3633a49a8412a43e5;
    reference:md5,304d1ac0296fedec694a097480b341d9;
    classtype:trojan-activity;
    sid:2032886; rev:1;
    metadata:attack_target Client_Endpoint, created_at 2021_04_28, deployment Perimeter, performance_impact Low, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2021_04_28;
)