What is wuauclt.exe and wuaudt.exe

Are you confused about the difference between wuauclt.exe and wuaudt.exe?

The two executable files wuauclt.exe and wuaudt.exe are the same processes. Part of the confusion is that when both "wuauclt.exe" and "wuaudt.exe" are in lowercase they look very similar. The letters "cl" look like a letter "d" depending on the way windows is setup to display your text such as having anti-aliasing text enabled.

What does the wuauclt.exe and wuaudt.exe file do?

The process wuauclt.exe can be a legitimate Windows Update process file or it can be a Trojan. The running process wuauclt.exe is an AutoUpdate process for Windows in its legitimate form. It runs in the background to check for updates whenever you are connected to the internet.

In the form of a Trojan wuauclt.exe or wuaudt.exe can perform various malicious activities on your computer from logging your account information to creating annoying popup advertisements. It is recommended to use a good spyware scan tool so it may identify wuauclt.exe or wuaudt.exe as a legitimate Windows process or a Trojan. Usually when wuauclt.exe or wuaudt.exe are in the form of a Trojan it is the Cult-B or Backdoor.Clt Trojan part of the W32.Cult group of Trojans. It is known to infect Windows 95, Windows 98, Windows ME, Windows 2000, Windows NT and Windows XP.

PC Tip: Hackers use common process file names such as wuauclt.exe or wuaudt.exe to mask a malicious file. Wuauclt.exe and wuaudt.exe happen to be the same type of file with different spellings. This gives hackers an easy outlet to fool users who are able to identify suspicious processes running on their computer. In our previous article on How To Investigate Windows Processes you can find out ways to decipher if a running process is legitimate or not. An easy way to determine if the wuauclt.exe or wuaudt.exe processes are Trojans is by disabling Automatic Updates. If one of the two files is still present in your running processes after Automatic Updates is shut off then it may be a Trojan file.

Steps to turn off Automatic Updates

  1. Go to the Start menu
  2. Select Run
  3. Type in services.msc
  4. Press enter
  5. Right Click Automatic Updates
  6. Go to Properties
  7. Select Disable as the startup type
  8. Click OK

If you suspect that a running process file is a Trojan you can search the www.spyware-techie.com website for the associated Trojan for removal.

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  • http://spyware-techie.com Patrick Gregory

    wuauclt.exe I am disabling it on Startup.

  • Naomi

    This was a very helpful post. Not only did I follow your directions to disable this process, but I went through all of them on my list deciding what to keep automatic, what to disable, and what to leave as a manual option.


  • techiegal

    in XP, services.msi, you will see that the name of the executable is "wuauserv" rather than wuauclt dot exe or wuaaudt dot exe. you can stop the service, but of course there are consequences, and you should read up on them. you can set the service wuauserv to be executed manually. however, read the description in services.msc > automatic updates when you highlight the service, before you select properties, to determine whether or not you truly want to disable automatic startup.

  • Drakhir

    Very useful, thank you. It is quite staggering how many types of file from the operating system cripple the use of the very thing they are supposed to streamline! Thanks to people like you, we can unclutter the rubbish that Micro-soft foister on us.

  • Scotty

    Thank you for this. I disabled wuaudt.exe because it kept "spiking" and using a lot of my limited RAM. Thankfully I ordered more RAM a few days ago, and it should be arriving today. Once it gets here, I 'll re-enable wuaudt.exe, as it shouldn't make much difference then.

  • Michael Boyle

    So, I turned off automatic updates.
    Now, how do I turn off all the messages telling me that my computer might be at risk because automatic updates is turned off?