alert tls $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Observed Oyster Backdoor Domain (techwisenetwork .com) in TLS SNI"; flow:established,to_server; tls.sni; dotprefix; content:".techwisenetwork.com"; endswith; fast_pattern; reference:url,malasada.tech/oyster-malware-delivery-via-teams-fake-app/#references; classtype:domain-c2; sid:2064984; rev:1; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_and_Server, created_at 2025_09_30, deployment Perimeter, malware_family Oyster, performance_impact Low, confidence High, signature_severity Major, updated_at 2025_09_30, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1041, mitre_technique_name Exfiltration_Over_C2_Channel;)