DNS Query Monitoring
uberAgent ESA monitors outgoing DNS queries and their responses. This includes all DNS queries that are processed by the operating system.
The implementation and functionality of DNS query monitoring differ between operating systems.
uberAgent uses the local DNS machine’s DNS resolver as the data source. uberAgent sees all DNS requests that are handled by the OS, including requests via encrypted DNS (DoT or DoH). uberAgent doesn’t see requests that bypass the OS resolver, e.g., requests from tools such as
uberAgent cannot differentiate between requests that go over the wire and requests that can be answered from the local DNS cache. Both types of requests are collected by uberAgent.
uberAgent monitors network traffic at the packet level. uberAgent sees any and all DNS requests, but it cannot process encrypted DNS (DoT or DoH). uberAgent only collects requests that go over the wire, it doesn’t process requests that can be answered from the local DNS cache.
uberAgent ESA DNS query monitoring is enabled or disabled through the timer metric
DnsMonitoring. For Windows clients, this feature requires Windows 8.1 or newer versions of Windows since the data source for this event is not available in previous Windows versions, such as Windows 7. Enabling the metric on unsupported Windows versions has no effect. For macOS, all versions are supported.
DNS query monitoring events are sent with the sourcetype
uberAgentESA:Process:DnsQuery (documentation). This feature may significantly increase the data volume and can be limited using event data filtering. uberAgent’s configuration includes a comprehensive set of rules to exclude known and harmless DNS requests.
DNS monitoring events are also available via uberAgent’s Threat Detection engine. This allows the creation of rules to report specific DNS events (e.g., malicious events or threat detection).
DNS query monitoring events are visualized in the DNS Exfiltration and Tunneling dashboard, which is part of the
uberAgent_ESA Splunk searchhead app.