alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE CHERRYSPY.Backdoor Russia APT28 Initial Key Exchange"; flow:established,to_server; flowbits:set,ET.CherrySpy.Backdoor.KeyExchange; http.method; content:"POST"; http.request_body; content:"|7b|"; startswith; content:"|22|USR_KAF|22 3A|"; fast_pattern; content:"|22|USR_CRC|22 3A|"; content:"|22|USR_PUB|22 3A|"; content:"|7d|"; endswith; reference:url,go.recordedfuture.com/hubfs/reports/CTA-RU-2024-1121.pdf; reference:url,cert.gov.ua/article/4697016; classtype:trojan-activity; sid:2062546; rev:1; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, affected_product Windows_11, attack_target Client_and_Server, tls_state plaintext, created_at 2025_05_22, deployment Perimeter, malware_family CHERRYSPY, performance_impact Low, confidence High, signature_severity Major, tag APT28, updated_at 2025_05_22, mitre_tactic_id TA0037, mitre_tactic_name Command_And_Control, mitre_technique_id T1041, mitre_technique_name Exfiltration_Over_C2_Channel; target:src_ip;)