The 'ESXi Download Errors' detection rule identifies failed file download attempts on VMware ESXi hosts by analyzing specific error messages found in the system logs. Such failures may signify unauthorized or malicious attempts to install or update components, which could include VIBs (vSphere Installation Bundles) or malicious scripts that attackers deploy post-compromise. The rule is built on logs from the VMWare ESXi Syslog and leverages searches for common download failure messages, aggregating error instances to pinpoint problematic destinations. The implementation necessitates configuring ESXi systems to forward their syslog outputs to a Splunk deployment with the requisite Splunk Technology Add-on for VMware ESXi Logs to ensure proper data ingestion and field extractions, allowing for accurate detection and response.