alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE SysJoker CnC Checkin (POST)"; flow:established,to_server; urilen:8; http.method; content:"POST"; http.uri; content:"/api/req"; http.content_type; content:"application/x-www-form-urlencoded"; bsize:33; http.request_body; bsize:42; content:"token="; startswith; fast_pattern; pcre:"/^(?:(?:[a-z0-9]{8})\x2d(?:[a-z0-9]{4})\x2d(?:[a-z0-9]{4})\x2d(?:[a-z0-9]{4})\x2d(?:[a-z0-9]{12}))$/R"; reference:url,research.checkpoint.com/2023/israel-hamas-war-spotlight-shaking-the-rust-off-sysjoker; reference:url,intezer.com/blog/research/wildcard-evolution-of-sysjoker-cyber-threat; classtype:trojan-activity; sid:2049305; rev:2; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2023_11_27, deployment Perimeter, confidence Medium, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2024_01_31;)