ET MALWARE PurpleFox Backdoor/Rootkit Download Server Response M2

alert http $EXTERNAL_NET any -> $HOME_NET any (
    msg:"ET MALWARE PurpleFox Backdoor/Rootkit Download Server Response M2";
    flow:established,to_client;
    http.stat_code;
    content:"200";
    http.content_type;
    content:"application/octet-stream"; bsize:24;
    http.server;
    content:"HFS|20|"; startswith; fast_pattern;
    http.cookie;
    content:"HFS_SID_="; startswith;
    http.header;
    content:"|0d 0a|Content|2d|Disposition|3a 20|attachment|3b 20|filename|2a 3d|UTF|2d|8|27 27|";
    content:"|2e|zip|3b 20|filename="; distance:1; within:15;
    content:"|2e|zip"; distance:1; within:4; endswith;
    http.response_body;
    content:"PK|03 04|"; startswith;
    content:"|2e|exe"; within:150;
    reference:url,blog.minerva-labs.com/malicious-telegram-installer-drops-purple-fox-rootkit;
    classtype:command-and-control;
    sid:2034872; rev:2;
    metadata:attack_target Client_Endpoint, created_at 2022_01_07, deployment Perimeter, malware_family PurpleFox, performance_impact Significant, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2022_01_10;
)