alert http [$HOME_NET,$SMTP_SERVERS] any -> any any (msg:"ET MALWARE JS SpyPress C2 Success Callback (cURL)"; flow:established,to_server; http.request_line; content:"GET /?se=cu"; fast_pattern; startswith; http.user_agent; content:"curl|2f|"; http.method; content:"GET"; reference:url,www.proofpoint.com/us/blog/threat-insight/ta458-roundpress-exploits; classtype:trojan-activity; sid:2071253; rev:1; metadata:attack_target Client_Endpoint, created_at 2026_07_21, deployment Perimeter, malware_family SpyPress, confidence High, signature_severity Major, tag c2, updated_at 2026_07_21, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1071, mitre_technique_name Application_Layer_Protocol; target:src_ip;)