alert dns $HOME_NET any -> any any (msg:"ET RETIRED SecShow Domain DNS Lookup (secdns .site)"; dns.query; dotprefix; content:".secdns.site"; nocase; endswith; reference:url,unit42.paloaltonetworks.com/three-dns-tunneling-campaigns/; classtype:bad-unknown; sid:2052573; rev:2; metadata:affected_product Any, attack_target Client_Endpoint, created_at 2024_05_13, deployment Perimeter, former_category MALWARE, malware_family SecShow, performance_impact Low, confidence High, signature_severity Major, updated_at 2025_07_14, reviewed_at 2025_07_14;)