ET HUNTING Suspicious Zipped Filename in Outbound POST Request (cookie.txt) M1

alert http $HOME_NET any -> $EXTERNAL_NET any (
    msg:"ET HUNTING Suspicious Zipped Filename in Outbound POST Request (cookie.txt) M1";
    flow:established,to_server;
    http.method;
    content:"POST";
    http.request_body;
    content:"PK"; depth:2;
    content:"cookie.txt"; distance:26; within:50; nocase; fast_pattern;
    classtype:trojan-activity;
    sid:2027269; rev:2;
    metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_and_Server, created_at 2019_04_23, deployment Perimeter, performance_impact Low, confidence Medium, signature_severity Major, tag T1005, tag Data_from_local_system, tag Collection, updated_at 2020_08_28;
)