ET MALWARE [PTsecurity] Possible Cobalt Strike payload

alert http $EXTERNAL_NET any -> $HOME_NET any (
    msg:"ET MALWARE [PTsecurity] Possible Cobalt Strike payload";
    flow:established,from_server;
    http.stat_code;
    content:"200";
    http.header;
    content:"Content-Length|3a 20|";
    content:"|0d 0a|"; distance:5; within:4;
    file.data;
    content:"|fc e8 00 00 00 00 eb|"; depth:7; fast_pattern;
    classtype:targeted-activity;
    sid:2024771; rev:3;
    metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2017_09_27, deployment Perimeter, malware_family Cobalt_Strike, performance_impact Low, confidence Medium, signature_severity Major, updated_at 2020_08_28;
)