alert http [$HOME_NET,$SMTP_SERVERS] any -> any any (msg:"ET MALWARE JS ZimReaper C2 Exfiltration"; flow:established,to_server; http.request_line; content:"POST /v/d HTTP/"; fast_pattern; http.host; content:"js|2d|"; startswith; content:"|2e|i|2e|"; http.content_type; content:"application/octet-stream"; http.header; to_lowercase; content:"x-filename|3a 20|"; pcre:"/^(?:(?:zimbra_batch_analytics|telemetry_[^\x2e]+)\x2ejson|telemetrydata_[^\x2e]+\x2etgz)/R"; reference:url,www.proofpoint.com/us/blog/threat-insight/ta488-targets-zimbra-mailservers-half-click-exploits; classtype:trojan-activity; sid:2071244; rev:1; metadata:attack_target Client_Endpoint, created_at 2026_07_21, deployment Perimeter, malware_family ZimReaper, 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 T1041, mitre_technique_name Exfiltration_Over_C2_Channel; target:src_ip;)