CCleaner 5.33 virus (Removal Guide) - updated May 2020

CCleaner 5.33 virus Removal Guide

What is CCleaner 5.33 virus?

CCleaner v5.33 virus is the corrupted utility version that brings Floxif malware to 2.27 million users via a hacked executable file

CCleaner virus

CCleaner virus defines a corrupted v5.3 version of a well-known anti-malware tool CCleaner. By using the Advanced Persistent Threat (APT) type of attack[1], the perpetrators have managed to violate the distribution network and deliver malware in the disguise of a certified CCleaner 5.33 version.

The malware, which gained the name of Floxif Trojan[2], managed to deceive over 2 million users that they had downloaded a validated CCleaner version 5.33 and CCleaner Cloud 1.07.3191. The attack began on August 15 and lasted up to September 12, 2017, when security experts have managed to detect the felony.

The malware gets executed if the user was using the admin account, so low-privileged account users who have installed the CCleaner 5.33 file were not affected. This malware affected main accounts and administrative accounts of devices that got this malicious version of the tool.

Updating to 3.34 version can remove the corrupted file and the tool. But for those who want to be totally safe additional actions should be helpful. The infected computer should not be used until the machine is cleaned from malware, resetting passwords is highly advised to stop Floxif infection and attackers from running deeper into the system and stealing passwords or other sensitive details.

Name CCleaner 5.33 virus
Type Malware. the Floxif virus gets delivered via the corrupted version of a cleaner utility
Functions The virus can collect data from the machine and download or execute other malware directly in the background since it gains admin rights
Damage The threat can use stolen data to identify each unique device and attackers may target particular people with secondary payload drops. Having administrative rights on the computer means that hackers can easily download and launch scripts or programs directly on the system
Distribution Downloading the CCleaner version that was corrupted between August and September in 2017. Trojans can also use other methods of spreading like malicious files and other executables download via torrent services and fake program providers
Removal To remove CCleaner 5.33 virus, you need to get rid of the executable file itself. Updating to other versions may help, but malware should be eliminated using AV tools and security programs
Additional tips Even though updating to clean versions of the program can help with eliminating the trojan, other programs may be left behind or alterations that malware makes still trigger issues with your machine, so rely on FortectIntego or PC repair tools to check or even fix virus damage

Update September 28th, 2017. Though Avast who now owns the tool originally created by Piriform, has stated that the malware was terminated, it seems that the cyber criminals continued the assault. The first stage of the CC Cleaner virus attack sparked assumptions that the endpoint target was ordinary users. Floxif trojan which behaves as a backdoor virus was programmed to collect information about victims' and send the data to a remote server.

Due to the overload of the server, the database had crashed. It led malware developers to rebuild the database and initiate a second stage of the attack. It then revealed that ordinary users were only an intermediary chain to target major companies: Microsoft, Sony, Samsung, Cisco, VMware, D-Link, Linksys, HTC.

A recent analysis revealed over 700 000 devices were infected and approximately 20 companies have been infected with the malware within the span of 4 days.[3] Telecommunication and social network companies are among the most affected targets. The companies in Japan and Taiwan reported having the utmost number of infected computers – 10 and 13 – respectively.

Main facts about the Piriform malware (Floxif):

  • Floxif CCleaner Trojan was embedded in the 32-bit version of CCleaner 5.33.6162 and CCleaner Cloud 1.07.3191. The attackers added the malware into the main executable of the software, known as CCleaner.exe.
  • The malicious version was publicly available to download between August 15, 2017, and September 15, 2017. The company that owns the rights to the software reported that approximately 2.27 million people installed and used the compromised version of the PC optimization software.
  • The compromised version installed a backdoor to victim’s computers that was capable of transmitting certain data to C&C server.
  • Infected users should immediately update to 5.34 version of the software and take actions to change passwords and other sensitive data that criminals could have accessed.
  • Two IP addresses – and – are associated with the hackers.

Research suggests that updating might not be enough as criminals have included a previously undiscovered payload. Victims are advised to restore their computer from backups to erase the malware entirely.

The compromised version of CCleaner 5.33 included a malicious payload that contained a Domain Generation Algorithm (DGA) and ability to communicate with Command & Control (C&C) server. The virus used that connection to transmit all kinds of data from victim’s computer, including, but not limited to:

  • Computer’s name;
  • List of installed programs;
  • List of network adapters;
  • Unique IDs;
  • List of active processes.

To protect your computer and complete CCleaner virus removal, you must update from v5.33 to v.34 IMMEDIATELY. The impact of the malware is high, however, considering that the software manages to score up to 2 billion downloads per month, the situation could have been worse. CCleaner malwareFloxif is the name of the malware found in CCleaner 5.33 version.

Besides, the compromised version could have brought more malware to your computer (as it reportedly could do so), so we strongly recommend scanning your computer with anti-malware software to remove CCleaner Floxif Trojan remains and other dangerous programs at once. You may also need to repair some damage that the virus leftover, so rely on PC repair tools that are reliable like FortectIntego.

CCleaner malware begins its second payload

Researchers from Talos Intelligence have reported[4] a second CCleaner virus’ payload that was aimed at a limited number of high-profile tech companies based on their domains. Criminals tried to compromise one of the largest companies, including:

Akamai, Intel, Microsoft, Google, Samsung, Sony, VMware, HTC, Linksys, D-Link, Cisco.

The second payload starts with an installer called GeeSetup_x86.dll. Once activated, it determines what is the version of the system – 32 or 64-bit and then drops the trojan on it. The one for 32-bit version is called TSMSISrv.dll, and the other one is EFACli64.dll. It appears that malicious actors sought to steal intellectual property from the listed technology firms.

Transmission of the trojan-backdoor

As we specified before, original servers of CCleaner were compromised during the cyber attack, and it means that the malware was available to everyone who downloaded the software from Piriform’s website.

The updated version was released on August 15th, 2017, meaning that it was the date when users started to download the compromised version on their computers unknowingly. warns[5] that the same thing could have happened to anyone who installed an update for the PC optimization software between August 15 and September 15 of 2017.

Is CCleaner safe?

Note that Piriform[6] CCleaner program itself is NOT a virus. It is an entirely legitimate software that you can use, however, malicious actors used illegal methods to break into companies’ servers and inject malicious scripts into the signed software.

Right when security experts detected C Cleaner virus, Avast issued an official statement urging users and companies update to 5.34 version. However, there is still a lack of information how the perpetrators have managed to continue the assault.

In order to ensure that your computer is safe from the malware, uninstall the program, scan the system using a security tool, and reinstall CCleaner 5.34 version. Now let us discuss options how to remove CCleaner malware.

Perform CCleaner virus removal

Research suggests that it might not be enough to remove CCleaner virus by updating it to 5.34 version. Since the second payload was discovered, we recommend cleaning your computer fundamentally. Security tools like SpyHunter 5Combo Cleaner or Malwarebytes should help, or you can rely on more powerful AV programs.

Therefore, we recommend you to restore your computer from a backup (created before installation of the malware) and then double-check your PC with PC repair software like FortectIntego that can find affected files. You can find instructions on how to clean your computer below that include additional tips for rebooting the PC in Safe Mode, for example.

Once you complete CCleaner removal, protect the accounts that you accessed while the malicious version of computer optimization software was running on your PC. We strongly recommend you change your passwords using a device that wasn’t compromised – ideally, your phone.

do it now!
Fortect Happiness
Intego Happiness
Compatible with Microsoft Windows Compatible with macOS
What to do if failed?
If you failed to fix virus damage using Fortect Intego, submit a question to our support team and provide as much details as possible.
Fortect Intego has a free limited scanner. Fortect Intego offers more through scan when you purchase its full version. When free scanner detects issues, you can fix them using free manual repairs or you can decide to purchase the full version in order to fix them automatically.
Alternative Software
Different software has a different purpose. If you didn’t succeed in fixing corrupted files with Fortect, try running SpyHunter 5.
Alternative Software
Different software has a different purpose. If you didn’t succeed in fixing corrupted files with Intego, try running Combo Cleaner.

Getting rid of CCleaner 5.33 virus. Follow these steps

Manual removal using Safe Mode

Important! →
Manual removal guide might be too complicated for regular computer users. It requires advanced IT knowledge to be performed correctly (if vital system files are removed or damaged, it might result in full Windows compromise), and it also might take hours to complete. Therefore, we highly advise using the automatic method provided above instead.

Step 1. Access Safe Mode with Networking

Manual malware removal should be best performed in the Safe Mode environment. 

Windows 7 / Vista / XP
  1. Click Start > Shutdown > Restart > OK.
  2. When your computer becomes active, start pressing F8 button (if that does not work, try F2, F12, Del, etc. – it all depends on your motherboard model) multiple times until you see the Advanced Boot Options window.
  3. Select Safe Mode with Networking from the list. Windows 7/XP
Windows 10 / Windows 8
  1. Right-click on Start button and select Settings.
  2. Scroll down to pick Update & Security.
    Update and security
  3. On the left side of the window, pick Recovery.
  4. Now scroll down to find Advanced Startup section.
  5. Click Restart now.
  6. Select Troubleshoot. Choose an option
  7. Go to Advanced options. Advanced options
  8. Select Startup Settings. Startup settings
  9. Press Restart.
  10. Now press 5 or click 5) Enable Safe Mode with Networking. Enable safe mode

Step 2. Shut down suspicious processes

Windows Task Manager is a useful tool that shows all the processes running in the background. If malware is running a process, you need to shut it down:

  1. Press Ctrl + Shift + Esc on your keyboard to open Windows Task Manager.
  2. Click on More details.
    Open task manager
  3. Scroll down to Background processes section, and look for anything suspicious.
  4. Right-click and select Open file location.
    Open file location
  5. Go back to the process, right-click and pick End Task.
    End task
  6. Delete the contents of the malicious folder.

Step 3. Check program Startup

  1. Press Ctrl + Shift + Esc on your keyboard to open Windows Task Manager.
  2. Go to Startup tab.
  3. Right-click on the suspicious program and pick Disable.

Step 4. Delete virus files

Malware-related files can be found in various places within your computer. Here are instructions that could help you find them:

  1. Type in Disk Cleanup in Windows search and press Enter.
    Disk cleanup
  2. Select the drive you want to clean (C: is your main drive by default and is likely to be the one that has malicious files in).
  3. Scroll through the Files to delete list and select the following:

    Temporary Internet Files
    Recycle Bin
    Temporary files

  4. Pick Clean up system files.
    Delete temp files
  5. You can also look for other malicious files hidden in the following folders (type these entries in Windows Search and press Enter):


After you are finished, reboot the PC in normal mode.

Remove CCleaner 5.33 using System Restore

  • Step 1: Reboot your computer to Safe Mode with Command Prompt
    Windows 7 / Vista / XP
    1. Click Start Shutdown Restart OK.
    2. When your computer becomes active, start pressing F8 multiple times until you see the Advanced Boot Options window.
    3. Select Command Prompt from the list Select 'Safe Mode with Command Prompt'

    Windows 10 / Windows 8
    1. Press the Power button at the Windows login screen. Now press and hold Shift, which is on your keyboard, and click Restart..
    2. Now select Troubleshoot Advanced options Startup Settings and finally press Restart.
    3. Once your computer becomes active, select Enable Safe Mode with Command Prompt in Startup Settings window. Select 'Enable Safe Mode with Command Prompt'
  • Step 2: Restore your system files and settings
    1. Once the Command Prompt window shows up, enter cd restore and click Enter. Enter 'cd restore' without quotes and press 'Enter'
    2. Now type rstrui.exe and press Enter again.. Enter 'rstrui.exe' without quotes and press 'Enter'
    3. When a new window shows up, click Next and select your restore point that is prior the infiltration of CCleaner 5.33. After doing that, click Next. When 'System Restore' window shows up, select 'Next' Select your restore point and click 'Next'
    4. Now click Yes to start system restore. Click 'Yes' and start system restore
    Once you restore your system to a previous date, download and scan your computer with FortectIntego and make sure that CCleaner 5.33 removal is performed successfully.

Finally, you should always think about the protection of crypto-ransomwares. In order to protect your computer from CCleaner 5.33 and other ransomwares, use a reputable anti-spyware, such as FortectIntego, SpyHunter 5Combo Cleaner or Malwarebytes

How to prevent from getting malware

Stream videos without limitations, no matter where you are

There are multiple parties that could find out almost anything about you by checking your online activity. While this is highly unlikely, advertisers and tech companies are constantly tracking you online. The first step to privacy should be a secure browser that focuses on tracker reduction to a minimum.

Even if you employ a secure browser, you will not be able to access websites that are restricted due to local government laws or other reasons. In other words, you may not be able to stream Disney+ or US-based Netflix in some countries. To bypass these restrictions, you can employ a powerful Private Internet Access VPN, which provides dedicated servers for torrenting and streaming, not slowing you down in the process.

Data backups are important – recover your lost files

Ransomware is one of the biggest threats to personal data. Once it is executed on a machine, it launches a sophisticated encryption algorithm that locks all your files, although it does not destroy them. The most common misconception is that anti-malware software can return files to their previous states. This is not true, however, and data remains locked after the malicious payload is deleted.

While regular data backups are the only secure method to recover your files after a ransomware attack, tools such as Data Recovery Pro can also be effective and restore at least some of your lost data.

About the author
Olivia Morelli
Olivia Morelli - Ransomware analyst

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