ET MALWARE Possible FoggyWeb Backdoor Server Response

alert http $HOME_NET any -> $EXTERNAL_NET any (
    msg:"ET MALWARE Possible FoggyWeb Backdoor Server Response";
    flow:established,to_client;
    http.stat_code;
    content:"200";
    http.content_type;
    content:"image/webp"; bsize:10;
    file.data;
    content:"|52 49 46 46|"; startswith;
    content:"|57 45 42 50 56 50 38 20|"; distance:4; within:8;
    content:"|10 32 00 9d 01 2a|"; distance:4; within:6; fast_pattern;
    pcre:"/^[\x80|\x40]\x00[\x80|\x40]\x00\x00\x00/R";
    reference:url,www.microsoft.com/security/blog/2021/09/27/foggyweb-targeted-nobelium-malware-leads-to-persistent-backdoor;
    classtype:command-and-control;
    sid:2034036; rev:2;
    metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Server, created_at 2021_09_28, deployment Perimeter, deployment Internal, deployment SSLDecrypt, malware_family FoggyWeb, performance_impact Low, confidence Medium, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2021_09_28;
)