ET MALWARE W32/InstallMonster.Downloader Checkin

alert http $HOME_NET any -> $EXTERNAL_NET any (
    msg:"ET MALWARE W32/InstallMonster.Downloader Checkin";
    flow:established,to_server;
    http.method;
    content:"POST";
    http.uri;
    content:"/api";
    http.user_agent;
    content:"Mozilla/3.0|20|(compatible|3b 20|Indy Library)"; endswith; fast_pattern;
    http.protocol;
    content:"HTTP/1.0";
    http.header_names;
    content:!"Referer";
    content:!"Content-Type";
    reference:md5,70a6d9cb37e346b4dfd28bd4ea1f8671;
    classtype:command-and-control;
    sid:2017656; rev:6;
    metadata:created_at 2013_11_01, signature_severity Major, updated_at 2020_08_17;
)