Rule History

alert tls $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Observed Cobalt Strike CnC Domain (yuxicu .com in TLS SNI)"; flow:established,to_server; tls.sni; content:"yuxicu.com"; bsize:10; fast_pattern; reference:url,github.com/pan-unit42/tweets/blob/master/2021-08-09-BazarLoader-and-Cobalt-Strike-IOCs.txt; classtype:domain-c2; sid:2033699; rev:1; metadata:attack_target Client_Endpoint, created_at 2021_08_10, deployment Perimeter, malware_family Cobalt_Strike, performance_impact Low, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2021_08_10, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1071, mitre_technique_name Application_Layer_Protocol;)