Rule History

alert tls $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Observed Cobalt Strike CnC Domain (defenderupdateav .com in TLS SNI)"; flow:established,to_server; tls.sni; content:"defenderupdateav.com"; bsize:20; fast_pattern; reference:url,thedfirreport.com/2021/08/16/trickbot-leads-up-to-fake-1password-installation/; classtype:domain-c2; sid:2033799; rev:1; metadata:attack_target Client_Endpoint, created_at 2021_08_25, deployment Perimeter, malware_family Cobalt_Strike, confidence High, signature_severity Major, updated_at 2021_08_25, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1001, mitre_technique_name Data_Obfuscation;)