Cybersecurity & Information Security

Active Directory Logs: Key Information Sources for Investigation

6 min readPublished: August 5, 2026

Professional visual illustration of Active Directory Logs in Windows and Identity

Quick answer

Active Directory Logs require reading the full event, not just the Event ID: time, computer, user, Logon ID, Process, network source, and organizational context. The conclusion is formed by correlating multiple sources.

Windows and Identity investigations rely on a combination of authentication events, process creation, permission changes, Sysmon telemetry, and organizational context. A single event almost never provides a complete conclusion. This article focuses on Active Directory Logs and is intended for SOC analysts and Windows Server students. The goal is to provide a working method that can be applied in practice, in a professional interview, and in a work environment, without settling for a dictionary definition.

The main challenge is that data is almost always partial. 4768/4769 Kerberos, 4771 failures, 4740 lockout can indicate a direction, but their meaning depends on time, asset, user, and expected activity. Therefore, we will build the investigation around an investigation question, required evidence, and clear criteria for completion.

The practical scenario in the article is: Use Case table vs. Event IDs and source. All examples are lab data or process descriptions. When it comes to Penetration Testing, Web, or Cloud, work only with explicit authorization, defined scope, and the ability to stop the test.

What Systems Generate Telemetry

The topic 'What systems generate telemetry' is a central part of working with Active Directory Logs. It is recommended to break it down into three questions: What is the input, what decision do you want to make, and what evidence is sufficient to justify it. These questions prevent automatic tool usage without understanding the goal.

In practice, record 4768/4769 Kerberos, 4771 failures, 4740 lockout, 4728/4732 group changes, Directory Service log, compare to expected behavior, and define at least one pivot. The result should be verifiable by another analyst, including limitations and next steps.

Authentication and Kerberos

In Active Directory Logs, identity and authorization are two different questions: who is the client, and what are they allowed to do on the resource. You check Roles, Claims, Session, Object ownership, and changes throughout the lifecycle, rather than just assuming the user is 'logged in'.

A test matrix includes anonymous user, regular user, object owner, another user, and administrator. For each action, compare the Response and the server-side impact. Changing an identifier or Header is only a testing method; the evidence is whether the server approved or denied an action contrary to policy.

Account and Group changes

The topic 'Account and Group changes' is a central part of working with Active Directory Logs. It is recommended to break it down into three questions: What is the input, what decision do you want to make, and what evidence is sufficient to justify it. These questions prevent automatic tool usage without understanding the goal.

Directory Service and DNS

The topic 'Directory Service and DNS' is a central part of working with Active Directory Logs. It is recommended to break it down into three questions: What is the input, what decision do you want to make, and what evidence is sufficient to justify it. These questions prevent automatic tool usage without understanding the goal.

Correlation between DC and Endpoint

The topic 'Correlation between DC and Endpoint' is a central part of working with Active Directory Logs. It is recommended to break it down into three questions: What is the input, what decision do you want to make, and what evidence is sufficient to justify it. These questions prevent automatic tool usage without understanding the goal.

Unique Examination Focus Areas

In this topic, it is recommended to build a focused evidence map in advance. The main examination focus areas are: 4768/4769 Kerberos, 4771 failures, 4740 lockout, 4728/4732 group changes, Directory Service log. The list is not an automatic checklist; each item is chosen because it can link an entity, action, and time, or explain legitimate behavior.

4768/4769 Kerberos: Define what the expected value is, what would be considered abnormal, and what additional source would confirm the finding.
4771 failures: Define what the expected value is, what would be considered abnormal, and what additional source would confirm the finding.
4740 lockout: Define what the expected value is, what would be considered abnormal, and what additional source would confirm the finding.
4728/4732 group changes: Define what the expected value is, what would be considered abnormal, and what additional source would confirm the finding.
Directory Service log: Define what the expected value is, what would be considered abnormal, and what additional source would confirm the finding.

When one of the focus areas is unavailable, document the gap and choose an alternative. For example, if the Process identifier is not stable, you can use time, Host, User, and Parent; if the Payload is encrypted, use Metadata, volume, frequency, and TLS/DNS context.

Recommended Workflow

Define a Scope and a single working question regarding Active Directory Logs.
List the data sources and required evidence: 4768/4769 Kerberos, 4771 failures, 4740 lockout, 4728/4732 group changes.
Create a short Baseline of normal behavior or expected outcome.
Perform the minimum test in a lab environment and save time, input, and output.
Build a Timeline or comparison table and separate fact from interpretation.
Pivot to an additional source to confirm or refute the initial explanation.
Summarize the decision, limitations, recommended action, and Retest criterion.

Practical Scenario

The chosen scenario is a Use Case table vs. Event IDs and source. The purpose of the exercise is not to prove attack capability, but to practice collecting, comparing, and documenting in a safe manner. Before starting, define dummy data, a time window, and an expected outcome.

At the end of the exercise, submit a product that another analyst or tester can review: a screenshot or export of the evidence, a short Timeline, initial assumption, confirming evidence, limitation, and recommendation. When there is insufficient evidence, the correct conclusion is that the scenario was not proven.

Step	What is performed	Output
Preparation	Define Scope, time, and objective. List which fields or evidence from 4768/4769 Kerberos, 4771 failures, 4740 lockout are expected to appear.	Short test plan
Data creation	Perform a safe, simulated action related to Active Directory Logs, without real information or impact on a production system.	Controlled event/request/flow
Collection	Collect the raw evidence and context from another source. Ensure Time zone, identifiers, and integrity.	Two linked pieces of evidence
Analysis	Write what each piece of evidence proves, what it does not prove, and what is the possible legitimate explanation.	Interim conclusion
Completion	Choose closure, escalation, Finding, or Tuning; add recommendation and Retest.	Documented output

Practical Checklist

Check and document: Event ID and Provider.
Check and document: Computer, User, and Logon ID.
Check and document: Process, Parent, and Command Line.
Check and document: Source IP, Workstation, and Logon Type.
Check and document: Group/Privilege changes.
Check and document: Sysmon ProcessGuid or SessionGuid.
Note Time zone, tool version, and collection time.
Save the raw data before filtering or modification.
Write what the finding proves and what is still unknown.
Define owner and next action with a deadline.

Common Mistakes

Relying on Event ID without fields.
Confusing Logon with the source of attack.
Ignoring Logon Type.
Linking Processes by PID only.
Assuming all PowerShell is malicious.
Closing an event without checking the Domain Controller.

Summary and CTA

Active Directory Logs: Key Information Sources for Investigation is a topic that connects technical knowledge with work discipline. Start with a question, collect only relevant evidence, maintain context and time, and choose an action that can be justified and re-tested.

In HPI's Cybersecurity & AI track, these principles are practiced using systems, logs, and labs. A natural next step is to go through the linked articles, perform the lab exercise, and save the output as part of a professional portfolio.

FAQ

Does Active Directory Logs alone prove an attack or vulnerability?

No. It provides a signal or a finding that requires context, validation, and an additional source. A professional conclusion relies on a sequence of evidence and alignment with expected behavior.

What to do when some data is missing?

Document what is missing, check an alternative source, and reduce the level of certainty. Do not complete fields based on assumptions or present 'Unknown' as valid.

How long should evidence be retained?

Retention time depends on policy, regulation, cost, and event type. It is important to define Retention, Legal hold, and the ability to export evidence in a verifiable format in advance.

How to practice without endangering a real system?

Use virtual machines, simulated data, CTF, or a dedicated lab. In authorized tests, define Scope, Stop conditions, and backup before starting the work.