Detects Windows endpoints where two or more distinct remote monitoring and management (RMM) vendors are observed starting processes within the same time bucket. Each known RMM binary is mapped to a single vendor label; multiple binaries from the same vendor do not inflate counts. If two or more distinct vendors appear in the same nine-minute bucket (from now-9m with an 8m interval), an alert is generated. The rule aggregates by host.id and host.name and reports: number of distinct vendors (vendor_count), the list of vendors seen (vendors_seen), the executable names involved (processes_executable_values), and the first/last seen timestamps (first_seen, last_seen). Data sources span multiple telemetry endpoints (Elastic Defend, Sysmon, Winlogbeat, Windows Security events/forwarded events, Defender for Endpoint, SentinelOne, CrowdStrike FDR, Elastic Endgame) to populate process start events. This helps identify MSP environments with legitimate multi-vendor tooling as well as potential compromise, shadow IT, or attacker staging. The rule maps process.name to vendor labels using a comprehensive CASE mapping. A trigger is raised when vendor_count >= 2. The alert includes MITRE ATT&CK mapping to T1219 (Remote Access Tools) with a subtechnique for Remote Desktop Software, reflecting the technique of using multiple remote-access tools. Triage guidance covers verifying MSP usage versus compromise, correlating with related alerts, checking install sources and signatures, and validating asset inventory. False positives include legitimate MSP configurations with approved multi-vendor stacks or vendor mergers during migrations. Remediation guidance emphasizes isolating the host, inventorying remote-access software, removing unapproved tools, and enforcing a single approved RMM stack where feasible.