alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Win32/SparkRAT CnC Checkin (GET)"; flow:established,to_server; http.method; content:"GET"; http.uri; content:"/ws"; endswith; http.user_agent; content:"Go|2d|http|2d|client|2f|1|2e|1"; http.connection; content:"Upgrade"; bsize:7; http.header; content:"Key|3a 20|"; pcre:"/^(?:[a-z0-9]{64})\x0d\x0a/R"; content:"Sec|2d|WebSocket|2d|Version|3a 20|13|0d 0a|"; content:"UUID|3a 20|"; pcre:"/^(?:[a-z0-9]{32})\x0d\x0a/R"; content:"Upgrade|3a 20|websocket"; http.header_names; content:"|0d 0a|Host|0d 0a|User-Agent|0d 0a|Connection|0d 0a|Key|0d 0a|Sec-WebSocket-Key|0d 0a|Sec-WebSocket-Version|0d 0a|UUID|0d 0a|Upgrade|0d 0a 0d 0a|"; bsize:96; fast_pattern; threshold:type limit,track by_src,count 1,seconds 3600; reference:url,sangfor.com/farsight-labs-threat-intelligence/cybersecurity/may-hot-apt-security-events-techniques-tracker; classtype:command-and-control; sid:2046669; rev:2; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2023_06_27, deployment Perimeter, malware_family SparkRAT, confidence High, signature_severity Critical, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2023_11_10, reviewed_at 2024_01_26;)