alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Cobalt Strike X-Client Header (notevil)"; flow:established,to_server; http.request_header; header_lowercase; bsize:17; content:"x-client|3a 20|notevil"; fast_pattern; reference:url,cert.gov.ua/article/39708; classtype:trojan-activity; sid:2036282; rev:4; 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 2024_04_26, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1001, mitre_technique_name Data_Obfuscation;)