---
title: "How do you monitor and log unauthorized file access attempts?"  
description: "How do you monitor and log unauthorized file access attempts?"  
author: "ICSM Computer"  
published: 2025-05-16  
updated: 2025-05-25  
canonical: https://www.mindstick.com/forum/161630/how-do-you-monitor-and-log-unauthorized-file-access-attempts  
category: "c#"  
tags: ["c#", "file handling"]  
reading_time: 2 minutes  

---

# How do you monitor and log unauthorized file access attempts?

How do you monitor and [log](https://www.mindstick.com/articles/126269/the-main-uses-of-log-cabins) unauthorized [file access](https://www.mindstick.com/forum/157674/what-are-file-types-and-file-access-in-operating-systems) attempts?

## Replies

### Reply by Anubhav Sharma

Monitoring and logging unauthorized [file](https://www.mindstick.com/articles/59/encrypting-and-decrypting-files-using-c-sharp) [access](https://www.mindstick.com/articles/12994/how-foreigners-can-access-blocked-websites-in-china) attempts is crucial for system security and compliance. Here's a breakdown of how you can implement this across different platforms and environments:

## 1. Windows Systems

### Enable Auditing via Group Policy

1. Run `gpedit.msc` → Navigate to:\ `Computer Configuration > Windows Settings > Security Settings > Advanced Audit Policy Configuration > Object Access`
2. Enable:

   1. **Audit File System**
   2. Set it to **Success and Failure**.

### Set File/Folder Auditing

- Right-click the file/folder → **Properties** → **Security** → **Advanced**.
- Go to the **Auditing** tab → **Add**.
- Select the principal (e.g., Everyone or a specific user).
- Choose which actions to audit (e.g., "Read", "Write", "Delete", "Failed Access").

### View Logs

- Use **Event Viewer** → `Windows Logs > Security`.
- Look for events with ID **4656**, **4663**, **4660**, or **4658**.

## 2. Linux/Unix Systems

### Auditd (Linux Audit Daemon)

Install and configure `auditd`:

```plaintext
sudo apt install auditd audispd-plugins
```

### Add File Watch Rules

```plaintext
sudo auditctl -w /path/to/your/file -p rwxa -k unauthorized_access
```

- `-w`: watch this file
- `-p`: permissions (read, write, execute, attribute changes)
- `-k`: key to tag events for easier search

### View Logs

```plaintext
sudo ausearch -k unauthorized_access
```

Or check the audit log:

```plaintext
sudo less /var/log/audit/audit.log
```

### Permanent Rules

Add rules to `/etc/audit/rules.d/audit.rules`.

## 3. Application-Level Monitoring (Cross-Platform)

If you want to implement monitoring in a **custom application**, you can:

## Wrap File Access in Logic

- Check user credentials or permissions before opening a file.
- Log every failed attempt with timestamp, user, and action.

Example in C#:

```cs
try
{
    var user = GetCurrentUser();
    if (!UserHasAccess(user, filePath))
    {
        LogUnauthorizedAttempt(user, filePath);
        throw new UnauthorizedAccessException("Access denied.");
    }
    var fileContent = File.ReadAllText(filePath);
}
catch (UnauthorizedAccessException ex)
{
    logger.LogWarning($"Unauthorized access by {user} to {filePath} at {DateTime.Now}");
}
```

## 4. Third-Party Tools

- **SIEM tools** (Splunk, Elastic Stack, etc.): For centralized log collection and real-time alerting.
- **File Integrity Monitoring (FIM)** tools: Tripwire, OSSEC, AIDE.

## Best Practices

- Alert on multiple failed attempts.
- Combine with intrusion detection/prevention systems (IDS/IPS).
- Use timestamps, user context, and source IP in logs.
- Secure your logs to prevent tampering.


---

Original Source: https://www.mindstick.com/forum/161630/how-do-you-monitor-and-log-unauthorized-file-access-attempts

Copyright © MindStick Software Pvt. Ltd. This Markdown version is provided for developers, AI systems, and offline reading.