Detecting Brute-Force Attacks via Windows Event ID 4625
A security analyst reviewing Windows Security Event Logs sees multiple Event ID 4625 entries for a single user account, followed by a successful Event ID 4624. The account is a domain administrator. What is the MOST likely explanation?
Quick Answer
The answer is that an attacker performed a brute-force password attack and succeeded. This conclusion is drawn from the forensic pattern of multiple Event ID 4625 entries—each representing a failed logon attempt—followed by a single Event ID 4624, which records a successful logon. In a brute-force attack detection scenario, the rapid succession of 4625 failures against the same domain administrator account indicates systematic password guessing, and the subsequent 4624 confirms the attacker found the correct credential. On the Computer Hacking Forensic Investigator CHFI exam, this sequence tests your ability to correlate authentication failures with a successful breach, a common forensic artifact in incident response. A frequent trap is dismissing the 4624 as a legitimate user finally typing the correct password, but in a brute-force context, the clustered failures and the privileged target make compromise the most likely explanation. Memory tip: think “4625s are the hammer, 4624 is the door opening”—if the hammer stops and the door opens, someone broke in.
⚠ Common exam trap
A common mix-up: candidates confuse a brute-force attack (multiple failures from a single account) with a user simply mistyping their password, but the key differentiator is the volume of failures and the targeted nature of a domain administrator account, which is a high-value target for attackers.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
An attacker performed a brute-force password attack and succeeded
Event ID 4625 indicates a failed logon attempt, while Event ID 4624 indicates a successful logon. A sequence of multiple 4625 events for the same domain administrator account followed by a single 4624 event is the classic signature of a successful brute-force password attack, where an attacker systematically tries passwords until one works. The fact that the account is a domain administrator makes it a high-value target, and the pattern of failures then success is inconsistent with simple user error or misconfiguration.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
The user typed their password incorrectly several times before succeeding
Why it's wrong here
A domain administrator is unlikely to mistype a password that many times in quick succession; this is more indicative of an automated attack.
- ✗
The system experienced a denial of service attack
Why it's wrong here
DOS attacks do not typically generate repeated failed logon events followed by success.
- ✓
An attacker performed a brute-force password attack and succeeded
Why this is correct
Multiple failed logon attempts followed by a successful logon, especially on a privileged account, strongly suggests a brute-force attack.
- ✗
A misconfigured application caused repeated logon attempts
Why it's wrong here
While possible, the pattern is classic for brute-force, especially with a privileged account.
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Same concept, more angles
2 more ways this is tested on CHFI
These questions test the same concept from different angles. Work through them to make sure you can recognise it however the exam phrases it.
Variation 1. A security analyst is reviewing Windows Security Event Logs and notices multiple Event ID 4625 entries for a single user account within a short time frame. What does this MOST likely indicate?
easy- ✓ A.Brute-force password guessing attack
- B.Service installation
- C.Account lockout policy change
- D.Successful account logon
Why A: Event ID 4625 indicates a failed logon attempt. Multiple failures in a short time suggest a brute-force attack against the user account.
Variation 2. A security analyst reviews Windows Security Event Log and notices multiple Event ID 4625 entries for a single user account from various IP addresses within a short time frame. What is the MOST likely attack being attempted?
easy- ✓ A.Brute-force password attack
- B.Kerberos golden ticket attack
- C.ARP spoofing attack
- D.Pass-the-hash attack
Why A: Event ID 4625 indicates a failed logon attempt. Multiple such events for a single user account from various IP addresses within a short time frame is the classic signature of a brute-force password attack, where an attacker tries many passwords against one account from multiple source IPs to evade rate-limiting or IP-based blocking.
JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This CHFI practice question is part of Courseiva's free EC-Council certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the CHFI exam.