alert tls $HOME_NET any -> $EXTERNAL_NET any (msg:"ET PHISHING TA427/Kimsuky Domain in TLS SNI"; flow:established,to_server; tls.sni; bsize:12; content:"simos.online"; fast_pattern; reference:url,www.cyberresilience.com/threatintel/apt-group-kimsuky-targets-university-researchers/; classtype:misc-activity; sid:2055062; rev:1; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2024_08_08, deployment Perimeter, performance_impact Low, confidence High, signature_severity Major, tag Kimsuky, tag TA427, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2024_08_09, reviewed_at 2025_01_06, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1071, mitre_technique_name Application_Layer_Protocol;)