ET HUNTING Request for .bin with BITS/ User-Agent

alert http $HOME_NET any -> $EXTERNAL_NET any (
    msg:"ET HUNTING Request for .bin with BITS/ User-Agent";
    flow:established,to_server;
    http.uri;
    content:".bin"; endswith;
    http.user_agent;
    content:"Microsoft BITS/"; depth:15; fast_pattern;
    http.host;
    content:!"microsoft.com";
    content:!"pdfcomplete.com";
    content:!"mymitchell.com";
    content:!"azureedge.net";
    http.accept;
    content:"*/*"; depth:3; endswith;
    http.header_names;
    content:!"Referer";
    classtype:bad-unknown;
    sid:2024420; rev:10;
    metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, affected_product Microsoft_Word, attack_target Client_Endpoint, created_at 2017_06_23, deployment Perimeter, performance_impact Moderate, confidence Medium, signature_severity Major, updated_at 2020_09_16;
)