alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Win64/CobaltStrike.Beacon.J CnC Checkin"; flow:established,to_server; http.uri; content:"/apiv8/"; startswith; http.header; content:"|0d 0a|X-Client: notevil|0d 0a|"; fast_pattern; http.header_names; content:!"Referer"; reference:url,cert.gov.ua/article/39708; classtype:trojan-activity; sid:2036281; rev:3; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2022_04_20, deployment Perimeter, malware_family Cobalt_Strike, confidence Medium, signature_severity Major, updated_at 2023_03_14, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1001, mitre_technique_name Data_Obfuscation;)