If your computer is infected with malware, a message that says "Your browser has been blocked" may appear in your browser. The malware asks you to pay a certain amount to unlock your browser; however, you can unlock it without paying anything by either restarting or exiting your browser on Windows and Mac OS X.
Steps
Method 1 of 3: Unblock your browser on Windows

Step 1. Right click on the Windows taskbar on your desktop

Step 2. Click "Start Task Manager"
The Task Manager window will open on your screen

Step 3. Click on the Processes tab, then click on “Show processes from all users”

Step 4. Click on the process that your browser is running at the moment
For example, if you are using Google Chrome as your browser, click on “Chrome.exe”.

Step 5. Select “End Process” from the floating menu that appears on the screen

Step 6. Click "End Process" again when asked to confirm if you want to end the process

Step 7. Click "Yes" to finish the process
The next time you open the browser it will no longer be blocked.
Method 2 of 3: Restore your browser on Mac OS X

Step 1. Click on “Safari” and select “Restore Safari”
If you use Firefox, click on "Help> Troubleshooting> Restore Firefox."

Step 2. Verify that all items are checked in the Restore dialog box and click “Restore”
Your browser will be restored and will no longer be blocked.
Method 3 of 3: Force Quit Your Browser on Mac OS X

Step 1. Press the Command, Option, and Escape keys at the same time on your Mac computer
The Force Close window will appear on the screen.

Step 2. Select the browser that the malware has blocked and click "Force Close"
Your browser will stop running and will no longer be blocked.
Advice
- Keep your antivirus and antimalware software up-to-date on your computer at all times so that you are protected against any malicious software attack. With anti-malware software, there will be less chance of getting viruses, malware, and ransomware on your computer.
- Check your computer for viruses or malware with updated antivirus or antimalware after you complete the steps outlined in this article to verify that no other malicious software is infecting your machine.
- You could also unblock your browser by disabling JavaScript. In order for the malware to block your browser, it needs to use JavaScript and it could stop running if you disable it immediately.