alert tls $HOME_NET any -> $EXTERNAL_NET any (msg:"ET INFO Observed URL Shortener Service Domain (tr .ee) in TLS SNI"; flow:established,to_server; tls.sni; dotprefix; content:".tr.ee"; endswith; fast_pattern; reference:url,tr.ee/; classtype:misc-activity; sid:2060809; rev:1; metadata:affected_product Any, attack_target Client_Endpoint, created_at 2025_03_12, deployment Perimeter, performance_impact Low, confidence High, signature_severity Informational, tag URL_Shortener, updated_at 2025_03_12, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1102, mitre_technique_name Web_Service;)