alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE EtherRAT Victim CnC Checkin (GET)"; flow:established,to_server; flowbits:set,ET.EtherRAT.ping; http.method; content:"GET"; http.uri; content:"/api/"; startswith; pcre:"/\x3d(?:[a-z0-9]{8}\x2d)(?:[a-z0-9]{4}\x2d)(?:[a-z0-9]{4}\x2d)(?:[a-z0-9]{4}\x2d)(?:[a-z0-9]{12})$/"; http.header_names; content:"|0d 0a|x-bot-server|0d 0a|"; nocase; fast_pattern; threshold:type limit,count 1,seconds 300,track by_src; reference:md5,544be46f232f0cacecf73cc1be65ce62; reference:url,sysdig.com/blog/etherrat-dprk-uses-novel-ethereum-implant-in-react2shell-attacks#enter-etherrat-a-four-stage-attack-chain; classtype:command-and-control; sid:2066687; rev:2; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, tls_state TLSDecrypt, created_at 2026_01_12, deployment Perimeter, deployment SSLDecrypt, malware_family EtherRAT, confidence High, signature_severity Critical, updated_at 2026_01_15, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1071, mitre_technique_name Application_Layer_Protocol; target:src_ip;)