alert tls $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Observed Buer Loader Domain (officewestunionbank .com in TLS SNI)"; flow:established,to_server; tls.sni; content:"officewestunionbank.com"; bsize:23; fast_pattern; reference:md5,61e213e717cc8e156cec79a7c1cd0c64; classtype:domain-c2; sid:2031610; rev:1; metadata:attack_target Client_Endpoint, created_at 2021_02_10, deployment Perimeter, malware_family Buer, performance_impact Low, confidence High, signature_severity Major, tag SSL_Malicious_Cert, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2021_02_10, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1071, mitre_technique_name Application_Layer_Protocol;)