alert tls $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Observed Card Skimmer CnC Domain in TLS SNI"; flow:established,to_server; tls.sni; dotprefix; content:".tags-manager.com"; endswith; fast_pattern; reference:url,blogs.akamai.com/2020/11/a-new-skimmer-uses-websockets-and-a-fake-credit-card-form-to-steal-sensitive-data.html; classtype:domain-c2; sid:2031205; rev:1; metadata:affected_product Web_Browsers, attack_target Client_Endpoint, created_at 2020_10_06, deployment Perimeter, performance_impact Low, confidence High, signature_severity Major, tag SSL_Malicious_Cert, tag CardSkimmer, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2020_10_06, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1071, mitre_technique_name Application_Layer_Protocol;)