alert tls $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Observed APT/SideWinder CnC Domain in TLS SNI"; flow:established,to_server; tls.sni; content:"cdn-gov.net"; bsize:11; reference:md5,a59df006d000b2ad5fb328e23a05ff43; classtype:domain-c2; sid:2030723; rev:1; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2020_08_24, deployment Perimeter, malware_family Sidewinder, confidence High, signature_severity Major, updated_at 2020_08_24, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1071, mitre_technique_name Application_Layer_Protocol;)