alert tcp $HOME_NET 7000 -> $EXTERNAL_NET any (msg:"ET MALWARE Zbtlink Router ENDLESSDOORS Shell Outbound (rctlbash)"; flow:established,to_client; content:"rctlbash"; depth:8; reference:url,www.vulncheck.com/blog/zbt-endlessdoors; reference:cve,2026-66747; classtype:trojan-activity; sid:2072284; rev:1; metadata:attack_target Networking_Equipment, tls_state TLSDecrypt, created_at 2026_09_28, cve CVE_2026_66747, deployment Perimeter, confidence High, signature_severity Unknown, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2026_09_28, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1071, mitre_technique_name Application_Layer_Protocol;)