Threat Hunting with Security Logs Explained

Threat Hunting with Security Logs is one of the most effective ways to detect hidden cyber attacks before they cause real damage. Instead of waiting for alerts, security analysts actively search through security logs to find suspicious behavior that traditional tools might miss .

This approach is essential for cybersecurity, networking, penetration testing, and SOC analysts, especially when working with Windows Security Event Logs.

What Is Threat Hunting and Why It Matters ​

Threat Hunting is a proactive security process where you manually analyze logs and system activity to uncover:

• Failed login attacks
• Privilege escalation attempts
• Persistence techniques
• Unauthorized account or service creation

The biggest advantage?
You find the attacker before the alert fires .

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Why Security Logs Are Critical for Threat Hunting ​

Security Logs provide deep visibility into what is really happening inside a system, including:

• Login attempts
• Process execution
• Group membership changes
• Password and policy modifications

Analyzing these logs helps you:

• Detect attacks early
• Understand attacker behavior
• Reduce incident response time

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Important Windows Event IDs You Must Monitor ​

Failed Logons - Event ID 4625 ​

This event is key for detecting:

• Brute force attacks
• Credential stuffing
• Login attempts outside business hours

A high number of failures from one IP in a short time is a red flag.

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Kerberos Pre-Authentication Failed - Event ID 4771 ​

Usually indicates:

• Wrong password attempts
• Locked or expired accounts
• Password guessing attacks

Repeated failures from the same host may signal an active attack.

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Process Creation - Event ID 4688 ​

One of the most powerful events for Threat Hunting.
Helps detect:

• Malicious PowerShell usage
• Suspicious commands
• Living-off-the-land attacks (LOLBins)

Always correlate it with Event ID 4624 (successful logon).

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Security Log Cleared - Event ID 1102 ​

Extremely suspicious event.
Attackers often clear logs to hide their tracks after compromise.

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Service Installed - Event ID 4697 ​

Indicates:

• New service installation
• Potential persistence technique

Always verify service name, path, and creator.

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Scheduled Task Created - Event ID 4698 ​

Commonly abused for:

• Malware persistence
• Backdoor execution

If the task is not approved → investigate immediately.

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Local User Account Created - Event ID 4720 ​

This event shows:

• New local account creation
• Possible unauthorized access setup

High risk if created outside maintenance windows.

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Security Group Membership Changed - Event IDs 4728 / 4732 ​

Indicates:

• User added to privileged groups
• Possible privilege escalation

Always review Administrators and other sensitive groups.

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PowerShell Example: Detect Brute Force Attacks ​

Get-WinEvent -FilterHashtable @{
 LogName = 'Security'
 Id = 4625
} | Group-Object IpAddress | Sort-Object Count -Descending

This helps identify IP addresses with the most failed login attempts.

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PowerShell Example: Find Suspicious Processes ​

Get-WinEvent -FilterHashtable @{
 LogName = 'Security'
 Id = 4688
} | Where-Object {
 $_.Message -match "powershell|cmd|rundll32|netsh"
}

This detects potentially malicious command execution.

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Best Practices for Effective Threat Hunting ​

Correlate multiple events together
Know what “normal” looks like
Exclude approved admin activity
Document every finding

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Final Thoughts ​

Threat Hunting with Security Logs is a must-have skill for anyone working in:

• Cybersecurity
• SOC operations
• Network security
• Penetration testing

By understanding Windows Event IDs and analyzing logs the right way, you can stop attackers before real damage happens .