ET MALWARE ELF/Roboto - Possible Encrypted Roboto P2P Payload Requested M1

alert http $HOME_NET any -> $EXTERNAL_NET any (
    msg:"ET MALWARE ELF/Roboto - Possible Encrypted Roboto P2P Payload Requested M1";
    flow:established,to_server;
    http.method;
    content:"GET";
    http.uri;
    content:"/roboto."; fast_pattern;
    pcre:"/^tt[cf]$/R";
    http.user_agent;
    content:!"Windows";
    http.header_names;
    content:!"|0d 0a|Referer|0d 0a|";
    reference:url,blog.netlab.360.com/the-awaiting-roboto-botnet-en/;
    classtype:command-and-control;
    sid:2029040; rev:3;
    metadata:affected_product Linux, created_at 2019_11_21, deployment Perimeter, deployment Internal, malware_family Roboto, performance_impact Low, confidence Medium, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2021_08_06;
)