alert tls $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Observed ELF/HabitsRAT CnC Domain in TLS SNI"; flow:established,to_server; tls.sni; content:"xaxaxa-shadowserver-losers.brian-krebs-erectile-dysfunction.com"; bsize:63; fast_pattern; reference:md5,83d664b0078d46952baf9ee1d8732d7a; reference:url,twitter.com/michalmalik/status/1435918937162715139; classtype:domain-c2; sid:2033920; rev:1; metadata:affected_product Linux, attack_target Client_Endpoint, created_at 2021_09_10, deployment Perimeter, malware_family ELF_HabitsRAT, confidence High, signature_severity Major, tag SSL_Malicious_Cert, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2021_09_10, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1071, mitre_technique_name Application_Layer_Protocol;)