alert tls $EXTERNAL_NET any -> $HOME_NET any (msg:"ET MALWARE SteamStealer Malicious SSL Certificate Detected"; flow:established,to_client; tls.cert_subject; content:"CN=steamdesktopauthenticator.com"; fast_pattern; reference:url,bartblaze.blogspot.co.uk/2018/02/fake-steam-desktop-authenticator-steals.html; classtype:domain-c2; sid:2025388; rev:4; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_and_Server, created_at 2018_02_26, deployment Perimeter, malware_family Steam_Stealer, performance_impact Low, confidence Medium, signature_severity Major, tag SSL_Malicious_Cert, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2023_03_13, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1071, mitre_technique_name Application_Layer_Protocol;)