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;)