alert tls $HOME_NET any -> $EXTERNAL_NET any (msg:"ET JA3 Hash - Suspected Cobalt Strike Malleable C2 M1 (set)"; flow:established,to_server; ja3.hash; content:"eb88d0b3e1961a0562f006e5ce2a0b87"; ja3.string; content:"771,49192-49191-49172-49171"; flowbits:set,ET.cobaltstrike.ja3; flowbits:noalert; classtype:command-and-control; sid:2028831; rev:1; 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, confidence Low, signature_severity Major, updated_at 2019_10_15, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1001, mitre_technique_name Data_Obfuscation;)