Cybersecurity & Information Security

Event ID 4624 and 4625: Investigating Successful and Failed Logons

7 min readPublished: August 5, 2026

Professional visual illustration of Event ID 4624 and 4625 in the field of Windows and Identity

Quick answer

Event IDs 4624 and 4625 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 several sources.

Windows and Identity investigation relies 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 Event ID 4624 and 4625 and is intended for junior SOC analysts. The goal is to provide a working methodology 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. Logon Type, TargetUserName, Source Network Address can point to a direction, but their meaning depends on the time, asset, user, and expected activity. Therefore, we will build the investigation around an investigative question, required evidence, and clear criteria for completion.

The practical scenario in the article is: analysis of a simulated series of logons. All examples are lab data or process descriptions. When it comes to Penetration Testing, Web, or Cloud, one should only work with explicit authorization, a defined Scope, and the ability to stop the test.

Meaning of 4624 and 4625

The topic 'Meaning of 4624 and 4625' is a central part of working with Event ID 4624 and 4625. 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 use without understanding the goal.

In practice, record the Logon Type, TargetUserName, Source Network Address, Workstation Name, Authentication Package, compare to expected behavior, and define at least one Pivot. The result should be verifiable by another analyst, including limitations and next steps.

Logon Types

The topic 'Logon Types' is a central part of working with Event ID 4624 and 4625. 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 use without understanding the goal.

Status and SubStatus

The topic 'Status and SubStatus' is a central part of working with Event ID 4624 and 4625. 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 use without understanding the goal.

Connecting Events by User and Source

At this stage, define what evidence is needed to answer the investigative question. For Event ID 4624 and 4625, the basic points are Event ID and Provider, Computer, User and Logon ID, Process, Parent and Command Line, Source IP, Workstation and Logon Type. For each source, document owner, retention range, time zone, reception delay, and fields that may be missing.

Collection quality is not measured by whether the log 'arrives'. Completeness, Latency, Parsing, Duplicate events, and time synchronization must be checked. A Canary test or a known lab event allows verifying that the action appeared in the source, passed through the Pipeline, and can be searched in the correct fields.

Suspicious Patterns vs. Failures

To understand the difference in the context of Event ID 4624 and 4625, it is important to compare goals, not just tools. One option provides breadth or speed, while another provides deep verification or context. The correct choice depends on the question: Is discovery, investigation, proof of impact, containment, or reporting required.

A professional comparison table should include at least: input type, certainty level, operational cost, potential impact, limitations, and required follow-up. In case of doubt, use the least intrusive approach and add a complementary source instead of drawing too broad a conclusion.

Unique Inspection Focuses

In this topic, it is recommended to build a focused evidence map in advance. The main inspection focuses are: Logon Type, TargetUserName, Source Network Address, Workstation Name, Authentication Package, Status, and SubStatus. The list is not an automatic Checklist; each item is chosen because it can link an entity, action, and time or explain legitimate behavior.

Logon Type: Define the expected value, what would be considered anomalous, and what additional source would verify the finding.
TargetUserName: Define the expected value, what would be considered anomalous, and what additional source would verify the finding.
Source Network Address: Define the expected value, what would be considered anomalous, and what additional source would verify the finding.
Workstation Name: Define the expected value, what would be considered anomalous, and what additional source would verify the finding.
Authentication Package: Define the expected value, what would be considered anomalous, and what additional source would verify the finding.
Status and SubStatus: Define the expected value, what would be considered anomalous, and what additional source would verify the finding.

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

Recommended Workflow

Define a Scope and one working question regarding Event ID 4624 and 4625.
Record the data sources and required evidence: Logon Type, TargetUserName, Source Network Address, Workstation Name.
Create a short Baseline of normal behavior or expected outcome.
Perform the minimal 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 criteria.

Practical Scenario

The chosen scenario is the analysis of a simulated series of logons. The purpose of the exercise is not to prove attack capability, but to practice safe collection, comparison, and documentation. Before starting, define simulated 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, an initial hypothesis, corroborating evidence, a limitation, and a recommendation. When there is insufficient evidence, the correct conclusion is that the scenario was not proven.

Stage	What to do	Output
Preparation	Define Scope, time, and goal. Record which fields or evidence from Logon Type, TargetUserName, Source Network Address are expected to appear.	Short test plan
Data Generation	Perform a safe and simulated action related to Event ID 4624 and 4625, without real information or impact on a production system.	Controlled event/Request/Flow
Collection	Collect the raw evidence and context from another source. Verify Time zone, identifiers, and completeness.	Two linked pieces of evidence
Analysis	Write what each piece of evidence proves, what it does not prove, and what the legitimate possible explanation is.	Interim conclusion
Completion	Choose closure, escalation, Finding, or Tuning; add a 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 the attack.
Ignoring Logon Type.
Linking Processes only by PID.
Assuming all PowerShell is malicious.
Closing an event without checking the Domain Controller.

Summary and CTA

Event ID 4624 and 4625: Investigating successful and failed logons 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-examined.

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

FAQ

Does Event ID 4624 and 4625 alone prove an attack or vulnerability?

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

What to do when some data is missing?

Document the missing data, check for an alternative source, and reduce the level of certainty. Do not complete fields based on assumption or present 'Unknown' as normal.

How long should evidence be kept?

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

How to practice without risking a real system?

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