ET INFO Adobe PDF in HTTP Flowbit Set

alert http $EXTERNAL_NET any -> $HOME_NET any (
    msg:"ET INFO Adobe PDF in HTTP Flowbit Set";
    flow:from_server,established;
    file_data;
    content:"%PDF-"; within:6;
    flowbits:set,ET.pdf.in.http;
    flowbits:noalert;
    reference:url,en.wikipedia.org/wiki/PDF;
    reference:url,en.wikipedia.org/wiki/List_of_file_signatures;
    reference:url,www.infosecinstitute.com/resources/hacking/pdf-file-format-basic-structure/;
    classtype:not-suspicious;
    sid:2015671; rev:11;
    metadata:affected_product Any, attack_target Client_Endpoint, tls_state plaintext, created_at 2010_09_25, deployment Perimeter, deployment Internal, deployment SSLDecrypt, performance_impact Low, confidence High, signature_severity Informational, tag File_Magic, updated_at 2025_01_30;
    target:src_ip;
)