alert tls $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Observed Blackrota Domain (blackrato .ga in TLS SNI)"; flow:established,to_server; tls.sni; content:"blackrato.ga"; bsize:12; fast_pattern; reference:url,blog.netlab.360.com/blackrota-an-obfuscated-backdoor-written-in-go-en/; classtype:domain-c2; sid:2031235; rev:1; metadata:attack_target Client_Endpoint, created_at 2020_11_25, deployment Perimeter, malware_family Blackrota, performance_impact Low, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2020_11_25, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1071, mitre_technique_name Application_Layer_Protocol;)