Microsoft Entra ID Sign-In Telemetry Reference

Microsoft Entra ID (formerly Azure AD) writes all sign-in activity to a family of Log Analytics tables that Sentinel ingests. Every record in every table carries OperationName = "Sign-in activity" regardless of the action involved. Because there is no per-operation discriminator, the tables cannot be modeled as discrete events the way Windows Security events are. Detections instead filter on field values within each table to distinguish success from failure, legacy from modern auth, and risky from compliant sessions.

Sign-In Log Tables#

CombinedSignInLogs is a Sentinel workspace function that unions all four tables into a single queryable surface. Rules targeting CombinedSignInLogs attribute to all four underlying tables.

Why There Are No Per-Operation Event Pages#

Each record in the sign-in tables carries OperationName = "Sign-in activity" without exception. The Entra audit pipeline does not emit separate operation names for "password auth", "MFA challenge", "token refresh", and so on. The result type, authentication method, and policy state are instead distributed across numeric and enumerated fields within each record.

Detections in the Sigma and Sentinel corpora that target sign-in logs pivot on these fields rather than on an operation name. The Azure AD Coverage matrix lists contributing rules under the "SigninLogs" section of that page.

Key Detection Fields#

ResultType Error Codes#

The most detection-relevant codes are listed here. The full list is maintained in the Microsoft Entra authentication and authorization error codes reference.

Legacy Authentication Detection#

Legacy authentication protocols (IMAP, POP3, SMTP, Exchange ActiveSync, MAPI over HTTP, AutoDiscover) do not support modern MFA flows. An adversary who obtains a password can authenticate using these protocols even when MFA is enforced on browser-based sign-ins.

Filter for legacy-auth sign-ins using ClientAppUsed:

SigninLogs
| where ClientAppUsed in ("IMAP", "POP3", "SMTP", "Mapi", "AutoDiscover",
                          "Exchange ActiveSync", "Other clients")
| where ResultType == "0"

Microsoft's recommended path to eliminate legacy auth is to block it via Conditional Access using the "Other clients" platform condition. Rules that detect legacy-auth successes after a tenant's block policy date are high-priority findings.

Relationship to the Microsoft Catalog#

Entra ID sign-in telemetry is non-Windows cloud telemetry. It does not produce Windows events and is not cataloged as event pages on this site. The /microsoft/ hub covers Windows events from the Microsoft-Windows-Security-Auditing and related providers, which record on-premises Kerberos and NTLM authentication separately.

For detection rules targeting sign-in logs, see:

References#