alert tls $EXTERNAL_NET [!25,!587] -> $HOME_NET any (msg:"ET DELETED Hash - Suspected Cobalt Strike Malleable C2 (ja3s) M1"; flow:established,from_server; ja3s.hash; content:"649d6810e8392f63dc311eecb6b7098b"; tls.cert_subject; content:!"servicebus.windows.net"; flowbits:isset,ET.cobaltstrike.ja3; classtype:command-and-control; sid:2028832; rev:4; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2019_10_15, deployment Perimeter, malware_family Cobalt_Strike, malware_family Cobalt_Strike, signature_severity Major, updated_at 2023_02_16, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1001, mitre_technique_name Data_Obfuscation;)