What is Win32/FakeSysDef

Win32/FakeSysDef, also known as Trojan:Win32/FakeSysdef, is a type of malware classified as a Trojan. It was first documented in late 2010 and targets the Microsoft Windows operating system. This malicious software masquerades as a legitimate system defragmentation tool, claiming to scan for hardware failures related to system memory, hard drives, and overall system performance. However, its real purpose is to deceive users into believing that their system is riddled with errors and hardware issues. The Trojan makes widespread changes to the system, which can include modifying Internet Explorer settings, changing the desktop wallpaper, hiding desktop and start menu links, disabling Windows Task Manager, and setting low-risk file types. During installation, it may terminate running processes and force a restart, then attempt to block every launched program, displaying fake error messages and prompting the user to purchase the fake software to fix the issues. The symptoms of a Win32/FakeSysDef infection are quite noticeable. Users will see numerous false alerts indicating system errors and the appearance of a system scan. The malware prompts the user to buy and activate a non-existent “Advanced Module” to fix the discovered errors. If the user agrees to purchase, they are directed to provide credit card information, either through an in-application form or by being redirected to a website.

Win32/FakeSysDef detection of windows defender

How Win32/FakeSysDef infected your system

The infection process of Win32/FakeSysDef is quite deceptive. It may arrive on a computer with various file names, often masquerading as a benign application. Upon execution, the installer drops and injects a DLL file or sometimes an EXE file into common processes such as “EXPLORER.EXE”, “WINLOGON.EXE”, and “WININET.EXE”. In some cases, it drops both DLL and EXE components, with the EXE set to run at every Windows restart and the DLL injected into “EXPLORER.EXE” by the EXE component. To ensure persistence, it places a copy of itself or its EXE component in the %APPDATA% folder using a random file name.

  1. Download Win32/FakeSysDef Removal Tool
  2. Use Windows Malicious Software Removal Tool to remove Win32/FakeSysDef
  3. Use Autoruns to remove Win32/FakeSysDef
  4. Files, folders and registry keys of Win32/FakeSysDef
  5. Other aliases of Win32/FakeSysDef
  6. How to protect from threats, like Win32/FakeSysDef

Download Removal Tool

Download Removal Tool

To remove Win32/FakeSysDef completely, we recommend you to use SpyHunter. It can help you remove files, folders, and registry keys of Win32/FakeSysDef and provides active protection from viruses, trojans, backdoors. The trial version of SpyHunter offers virus scan and 1-time removal for FREE.

Download Alternative Removal Tool

Download Malwarebytes

To remove Win32/FakeSysDef completely, we recommend you to use Malwarebytes Anti-Malware. It detects and removes all files, folders, and registry keys of Win32/FakeSysDef and several millions of other malware, like viruses, trojans, backdoors.

Remove Win32/FakeSysDef manually

Manual removal of Win32/FakeSysDef by inexperienced users may become a difficult task because it does not create entries in Add/Remove Programs under Control Panel, does not install browser extensions, and uses random file names. However, there are pre-installed instruments in the Windows system, that allow you to detect and remove malware without using third-party applications. One of them is Windows Malicious Software Removal Tool. It comes with Windows Update in Windows 11, 10, 8. 8.1. For older operating system you can download it here: 64-bit version | 32-bit version.

Remove Win32/FakeSysDef using Windows Malicious Software Removal Tool

  1. Type mrt in the search box near Start Menu.
  2. Run mrt clicking on found item.
  3. Click Next button.
  4. Choose one of the scan modes Quick scan, Full scan, Customize scan (Full scan recommended).
  5. Click Next button.
  6. Click on View detailed results of the scan link to view the scan details.
  7. Click Finish button.

Remove Win32/FakeSysDef using Autoruns

Win32/FakeSysDef often sets up to run at Windows startup as an Autorun entry or Scheduled task.

  1. Download Autoruns using this link.
  2. Extract the archive and run Autoruns.exe file.
  3. In Options menu make sure there are checkboxes near Hide Empty Locations, Hide Microsoft Entries, and Hide Windows Entries.
  4. Search for suspicious entries with weird names or running from locations like: C:\{username}\AppData\Roaming.
  5. Right-click on suspicious entry and choose Delete. This will prevent the threat to run at startup.
  6. Switch to Scheduled Tasks tab and do the same.
  7. To remove files themselves, click on suspicious entries and choose Jump to Entry…. Remove files or registry keys found.

Remove files, folder and registry keys of Win32/FakeSysDef

Win32/FakeSysDef files and folders


Win32/FakeSysDef registry keys

no information

Aliases of Win32/FakeSysDef


How to protect from threats, like Win32/FakeSysDef, in future

bitdefender internet security

Standard Windows protection or any decent third-party antivirus (Norton, Avast, Kaspersky) should be able to detect and remove Win32/FakeSysDef. However, if you got infected with Win32/FakeSysDef with existing and updated security software, you may consider changing it. To feel safe and protect your PC from Win32/FakeSysDef on all levels (browser, e-mail attachments, Word or Excel scripts, file system) we recommend a leading provider of internet security solutions – BitDefender. Its solutions both for home and business users proved to be one of the most advanced and effective. Choose and get your BitDefender protection via the button below:

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