ET MALWARE Possible BACKSWING JS Framework POST Observed

alert http $EXTERNAL_NET any -> $HOME_NET any (
    msg:"ET MALWARE Possible BACKSWING JS Framework POST Observed";
    flow:established,from_server;
    http.stat_code;
    content:"200";
    http.header;
    content:"Access-Control-Allow-Methods|3a 20|POST";
    http.content_type;
    content:"application/json"; startswith;
    file.data;
    content:"|7b 22|InjectionType|22 3a|"; depth:17; fast_pattern;
    content:"|22|InjectionString|22 3a 22|"; distance:0;
    reference:url,www.fireeye.com/blog/threat-research/2017/10/backswing-pulling-a-badrabbit-out-of-a-hat.html;
    classtype:trojan-activity;
    sid:2024932; rev:3;
    metadata:affected_product Web_Browsers, attack_target Client_Endpoint, created_at 2017_10_26, deployment Perimeter, confidence Medium, signature_severity Minor, updated_at 2020_08_13;
)