alert dns $HOME_NET any -> any any (msg:"ET INFO Free Hosting Domain in DNS Lookup (b4a .app)"; dns.query; dotprefix; content:".b4a.app"; nocase; endswith; reference:url,github.com/BadSamuraiDev/bs-lists/; classtype:misc-activity; sid:2068638; rev:1; metadata:affected_product Any, attack_target Client_and_Server, created_at 2026_04_08, deployment Perimeter, performance_impact Low, confidence High, signature_severity Informational, tag Free_Hosting, updated_at 2026_04_08, mitre_tactic_id TA0001, mitre_tactic_name Initial_Access, mitre_technique_id T1566, mitre_technique_name Phishing;)