alert dns $HOME_NET any -> any any (msg:"ET INFO DYNAMIC_DNS Query to a *.freeddns .tokyo domain"; dns.query; content:".freeddns.tokyo"; endswith; fast_pattern; nocase; reference:url,www.changeip.com/accounts/cart.php?a=add&bid=1; classtype:bad-unknown; sid:2065639; rev:1; metadata:attack_target Client_and_Server, created_at 2025_11_04, deployment Perimeter, confidence High, signature_severity Informational, updated_at 2025_11_04, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1568, mitre_technique_name Dynamic_Resolution;)