alert dns $HOME_NET any -> any any (msg:"ET HUNTING Observed DNS Query for OpenNIC Alternative DNS TLD (.dyn)"; content:"|01|"; offset:2; depth:1; content:"|00 01 00 00 00 00 00|"; distance:1; within:7; content:"|03|dyn|00|"; nocase; distance:0; fast_pattern; reference:url,wiki.opennic.org/opennic/dot; classtype:bad-unknown; sid:2029959; rev:2; metadata:attack_target Client_Endpoint, created_at 2020_04_20, deployment Perimeter, confidence High, signature_severity Informational, updated_at 2020_04_20;)