alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Zeus GameOver Checkin"; flow:established,to_server; http.method; content:"POST"; http.header; content:"X-ID|3a 20|"; http.host; content:"default"; fast_pattern; startswith; content:!"."; reference:md5,bd850c21254c33cd9f6be41aafc6bf46; classtype:command-and-control; sid:2018296; rev:4; metadata:created_at 2014_03_18, signature_severity Major, updated_at 2020_09_23;)