Use Defender for Identity sensor logs to reconstruct chronological sensor state

Frame this document as a source-led configuration and assurance check: Use Defender for Identity sensor logs to reconstruct chronological sensor state. Only the official source and traced locations below supply facts. Confirm applicability before acting.

Source fact:

The official Troubleshooting Microsoft Defender for Identity sensor using the Defender for Identity logs from Microsoft supports the following bounded statements:

• Defender for Identity logs provide point-in-time insight into sensor activity and status. The research record locates this support at Opening overview.
• The Microsoft.Tri.Sensor.log records sensor operations, resolution, and errors in chronological order and is used for an overall operational view. The research record locates this support at Sensor log descriptions.

These statements are the factual basis for this document. Do not extend them into a broader assurance. Review Defender for Identity workspaces, sensors, directory-service accounts, action accounts, network paths, roles, and deployment health only where the source and recorded environment align.

What the source does not establish

Logs can be incomplete or overwritten and do not by themselves prove root cause; preserve relevant files and correlate with system evidence. Do not read the source as proof of implementation or permission to change production. Its guidance remains conditional on Active Directory, Windows DNS, time, certificates, domain-controller resources, network capture, cloud connectivity, and security operations and the environment’s recorded constraints.

Applicability questions

• For source statement 1 at Opening overview, which observable configuration, record, or test can confirm applicability here?
• For source statement 2 at Sensor log descriptions, which observable configuration, record, or test can confirm applicability here?
• Which deployed instance of Defender for Identity workspaces, sensors, directory-service accounts, action accounts, network paths, roles, and deployment health will be compared with the source, and why that instance?
• How will the review distinguish a source mismatch from a failure in Active Directory, Windows DNS, time, certificates, domain-controller resources, network capture, cloud connectivity, and security operations?
• Who approves the conclusion, exception, test window, and rollback threshold?

DSE recommendation:

DSE recommends using the cited source as the evidence anchor for this decision. Start with applicability, then compare the observed state with the cited source. Record the source location, examined part of Defender for Identity workspaces, sensors, directory-service accounts, action accounts, network paths, roles, and deployment health, observed and expected states, owner, and reason for deviation.

For an approved change, define prerequisites, a limited test path, success and stop conditions, monitoring, and rollback. Check Active Directory, Windows DNS, time, certificates, domain-controller resources, network capture, cloud connectivity, and security operations in design order. Protect credentials, keys, recovery material, personal data, and sensitive topology in evidence.

Verification and evidence

Keep the source locations Opening overview; Sensor log descriptions adjacent to the sanitized artifacts used for comparison. Prefer sensor inventory, service and action-account permissions, health alerts, connectivity tests, portal state, and controlled detection tests, with enough identity and timing data for an independent recheck.

Preserve both successful and failed observations, along with approval and rollback evidence. Avoid uncontrolled production experiments. Assign an expiry or event-driven recheck so the conclusion is not treated as permanent.

Official references

• Troubleshooting Microsoft Defender for Identity sensor using the Defender for Identity logs — Microsoft