ET MALWARE Zacom/NFlog Checkin

alert http $HOME_NET any -> $EXTERNAL_NET any (
    msg:"ET MALWARE Zacom/NFlog Checkin";
    flow:to_server,established;
    http.method;
    content:"POST"; nocase;
    http.uri;
    content:".asp?HostID="; fast_pattern;
    pcre:"/\?HostID=([A-F0-9]{2}(?:-|<>)){5}[A-F0-9]{2}$/";
    http.header;
    content:"Windows NT 5.0|3b 20|.NET CLR 1.1.4322|29 0d 0a|";
    reference:md5,e397a68bf4fbb7a9b4d1b6da1fe2172b;
    reference:url,researchcenter.paloaltonetworks.com/2015/04/unit-42-identifies-new-dragonok-backdoor-malware-deployed-against-japanese-targets/;
    classtype:command-and-control;
    sid:2020928; rev:5;
    metadata:created_at 2015_04_16, signature_severity Major, updated_at 2020_09_30;
)