alert dns $HOME_NET any -> any any (msg:"ET INFO DYNAMIC_DNS Query to a *.dynu .net"; dns.query; content:".dynu.net"; endswith; fast_pattern; nocase; reference:url,www.dynu.com/ControlPanel/AddDDNS; classtype:bad-unknown; sid:2068992; rev:1; metadata:attack_target Client_and_Server, created_at 2026_04_27, deployment Perimeter, confidence High, signature_severity Informational, updated_at 2026_04_27, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1568, mitre_technique_name Dynamic_Resolution;)