ET HUNTING Suspicious Request for Doc to IP Address with Terse Headers

alert http $HOME_NET any -> $EXTERNAL_NET any (
    msg:"ET HUNTING Suspicious Request for Doc to IP Address with Terse Headers";
    flow:established,to_server;
    http.method;
    content:"GET";
    http.uri;
    content:".doc"; fast_pattern; nocase; endswith;
    http.host;
    pcre:"/^(?:\d{1,3}\.){3}\d{1,3}$/";
    http.header_names;
    content:"|0d 0a|Host|0d 0a|Connection|0d 0a 0d 0a|"; endswith;
    classtype:bad-unknown;
    sid:2025162; rev:5;
    metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2017_12_21, deployment Perimeter, confidence Medium, signature_severity Minor, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2020_09_17;
)