alert dns $HOME_NET any -> any any (msg:"ET INFO DYNAMIC_DNS Query to a *.whitesmurf .com domain"; dns.query; content:".whitesmurf.com"; endswith; fast_pattern; nocase; reference:url,freedns.afraid.org/domain/registry/page-10.html; classtype:bad-unknown; sid:2068568; rev:1; metadata:attack_target Client_and_Server, created_at 2026_04_03, deployment Perimeter, confidence High, signature_severity Informational, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2026_04_03, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1568, mitre_technique_name Dynamic_Resolution;)