This ES|QL rule detects when a single DNS client queries domains associated with two or more distinct Remote Monitoring and Management (RMM) vendors within a short window, which can indicate attacker testing, staging, or unauthorized remote access using legitimate management software. The rule normalizes vendor labels to group rebrands and aliases under a single vendor label, so multiple domains from the same product do not inflate the vendor count. It analyzes DNS-related data from multiple telemetry sources (Elastic network_traffic.dns, Fortinet FortiGate DNS logs, Suricata Eve DNS events, Zeek DNS logs, and legacy Packetbeat DNS) over a rolling window (from now-9m with an 8m interval) and aggregates by Esql.client_ip. The output includes Esql.event_count, Esql.rmm_vendor_count, Esql.rmm_vendor_values, Esql.dns_question_name_values, Esql.dns_registered_domain_values, Esql.dataset_values, Esql.first_seen, and Esql.last_seen, enabling correlation with endpoint telemetry and asset ownership. The alert triggers when at least two distinct RMM vendors are observed for a single client IP within the window, signaling potential staging, fallback access, or misuse of approved management software. The rule is intended for Network Security Monitoring and supports investigation by cross-referencing DNS activities with asset identity, DHCP leases, and related RMM/remote-access telemetry. It includes triage guidance and acknowledges false positives from MSP/helpdesk activity, migrations, software inventories, or browser-based DNS queries. Remediation guidance includes preserving evidence, isolating endpoints if unauthorized access is suspected, removing unauthorized RMM tools, rotating credentials, and enforcing an approved-RMM policy. The detection aligns with MITRE ATT&CK, specifically Remote Access Tools (T1219) and its subtechnique for Remote Desktop Software (T1219.002).