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How to Protect Your Computer by Removing CCleaner Malware

CCleaner is a popular optimization tool, but recent malware attacks have put millions of users at risk. As an experienced cybersecurity professional, I‘ll explain how to check for and eliminate CCleaner malware from your device. By taking a few important steps, you can securely use CCleaner again and avoid future malware headaches.

What is CCleaner and Why is it a Target?

CCleaner is a utility program from Piriform that cleans up junk files and invalid registry entries to optimize computer performance. It‘s freemium software with extra features available in paid versions. CCleaner has been trusted by consumers worldwide for decades.

But anything running on millions of computers presents an attractive target for cybercriminals. CCleaner‘s broad user base means infecting it with malware can stealthily compromise many victims. Three times in recent years, hackers have managed to inject malware into CCleaner updates.

History of CCleaner Malware Attacks

Cybercriminals have snuck malware into CCleaner in the following incidents:

  • September 2017 – CCleaner version 5.33 distributed malware to over 2 million users. The Floxif spyware stole data on running processes, while Trojan.Nyetya pilfered login credentials and financial information.

  • January 2019 – Malware again implanted in the 32-bit CCleaner 5.52 affecting 700,000 devices. The malware allowed remote access for further infection.

  • May 2021 – More malware strains found in latest CCleaner update, but detected quickly limiting damage.

These attacks exploited the software‘s vastReach to compromise users. According to Avastresearch, CCleaner
has been downloaded over 2 billion times
. With scale like that, hackers have plenty of incentive to find vulnerabilities.

How to Check if You Have CCleaner Malware

The clearest sign of infection is CCleaner behaving unexpectedly like crashing or freezing. But malware often lurks without symptoms.

To check properly, open CCleaner and look at the version number in the upper left corner. If you have 5.33.6162, 1.07.3191 or 5.52.6967, your version contains malware.

Here are other signs your device may be compromised:

  • Decreased performance like slow loading or freezing
  • Antivirus alerts detecting malware
  • Suspicious new processes in your Task Manager
  • Programs opening without your input
  • Pop-ups and ads outside your normal browsing

Don‘t ignore these warning signs. Run a scan to check for CCleaner malware or other threats.

Steps to Remove CCleaner Malware

If you have a compromised version or detect malware, here‘s how to comprehensively clean your computer:

1. Uninstall CCleaner

First, fully uninstall the infected CCleaner program:

  • Windows: Open Settings > Apps. Find CCleaner, select it and choose Uninstall.
  • Mac: Open Finder and locate CCleaner. Drag the app icon to your Trash. Empty Trash after.

This removes the original malware source, but more threats may remain.

2. Run Antivirus and Malware Scans

After uninstalling CCleaner, run full system scans using your installed antivirus software and supplementary malware removal tools like Malwarebytes. Set your antivirus to conduct thorough scans of all files, disks and connected drives. This detects any lingering malware payloads left on your system after removing CCleaner.

3. Clean Out Remaining Malware

The 2017 CCleaner attack installed the Floxif spyware and Trojan.Nyetya password stealer. Use your antivirus to quarantine these specific threats if found on your device.

4. Install Antivirus Protection

If you haven‘t already, install and set up a leading antivirus program to protect your computer from future malware. Top choices recommended by cybersecurity professionals include:

  • Bitdefender Antivirus – Provides excellent malware detection and ransomware protection.

  • Kaspersky Antivirus – Strong real-time defense against viruses, ransomware, spyware and more.

  • Norton 360 Antivirus – Blocks threats and includes a firewall, cloud backup and dark web monitoring.

Keeping your antivirus updated is crucial for identifying emerging malware strains like those that exploited CCleaner.

5. Change All Passwords

If your computer was compromised by Trojan.Nyetya or other password stealers, change all account passwords as a precaution once your device is clean. Enable two-factor authentication where available for extra security.

How to Avoid Malware Moving Forward

While CCleaner is now safe after addressing the malware issues, threats remain:

  • Update Software Frequently – Install updates and patches quickly to limit vulnerabilities.

  • Avoid Suspicious Downloads – Don‘t download from unverified sites, especially "cracked" or pirated software which often contains malware.

  • Run Regular Antivirus Scans – Schedule weekly full scans to catch malware early before major damage.

  • Use Reputable Security Software – Stick to trusted antivirus apps from major vendors like Norton, McAfee and Bitdefender.

  • Watch for Malicious Emails – Don‘t click links or attachments from unknown senders which can install malware.

Staying vigilant keeps your computer safe in an online world full of threats. Remove any CCleaner malware you discover promptly, and implement ongoing precautions.


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