alert tls $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Observed FIN12 Related Domain (hdhuge .com in TLS SNI)"; flow:established,to_server; tls.sni; content:"hdhuge.com"; bsize:10; fast_pattern; reference:md5,cf3027fa4e3d5597487691dff1831b97; reference:url,www.mandiant.com/resources/fin12-ransomware-intrusion-actor-pursuing-healthcare-targets; classtype:domain-c2; sid:2034182; rev:1; metadata:attack_target Client_Endpoint, created_at 2021_10_13, deployment Perimeter, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2021_10_13, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1071, mitre_technique_name Application_Layer_Protocol;)