.NET throwing strange errors on PC start up

Question

I've been getting this error on my PC all of a sudden and I can't seem to fix it. I've tried running the .NET repair tool and it just doesn't work. It happens each time I boot up my PC and it pushes my CPU quite high.

Any suggestions on what could be causing it?

Extra details:

See the end of this message for details on invoking 
just-in-time (JIT) debugging instead of this dialog box.
************** Exception Text **************
System.Net.WebException: The remote server returned an error: (404) Not Found.
   at System.Net.WebClient.DownloadDataInternal(Uri address, WebRequest& request)
   at System.Net.WebClient.DownloadString(Uri address)
   at System.Net.WebClient.DownloadString(String address)
   at ]g0&amp;LF*sX~,Emin0(tar!}nf*.‪‪⁫‬‏‍‬‌‍‌⁬⁫‪‬‫‎‌⁬‬‬‫⁯‏‫⁮‮‎‎⁪‎‫‍‬‎‏⁫‪‫‍‌‮(WebClient , String )
   at ]g0&amp;LF*sX~,Emin0(tar!}nf*.‌⁭⁬⁪⁬⁭‫‌‫‎⁬⁪‫‬‍‍‏‪‍‌‌⁭‬⁮⁫⁫‌⁯⁪‪⁫‫‪⁪⁭‍‍⁮⁮‮(Object , EventArgs )
   at System.Windows.Forms.Form.OnLoad(EventArgs e)
   at System.Windows.Forms.Form.OnCreateControl()
   at System.Windows.Forms.Control.CreateControl(Boolean fIgnoreVisible)
   at System.Windows.Forms.Control.CreateControl()
   at System.Windows.Forms.Control.WmShowWindow(Message& m)
   at System.Windows.Forms.Control.WndProc(Message& m)
   at System.Windows.Forms.ScrollableControl.WndProc(Message& m)
   at System.Windows.Forms.Form.WmShowWindow(Message& m)
   at System.Windows.Forms.Form.WndProc(Message& m)
   at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
   at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
   at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)
************** Loaded Assemblies **************
mscorlib
    Assembly Version: 4.0.0.0
    Win32 Version: 4.8.4300.0 built by: NET48REL1LAST_C
    CodeBase: file:///C:/Windows/Microsoft.NET/Framework/v4.0.30319/mscorlib.dll

CheckUpdate
    Assembly Version: 1.0.0.0
    Win32 Version: 13.9.0.0
    CodeBase: file:///C:/Users/Niishaw/AppData/Roaming/EventLog/CheckUpdate.exe

System.Windows.Forms
    Assembly Version: 4.0.0.0
    Win32 Version: 4.8.4270.0 built by: NET48REL1LAST_C
    CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/System.Windows.Forms/v4.0_4.0.0.0__b77a5c561934e089/System.Windows.Forms.dll

System
    Assembly Version: 4.0.0.0
    Win32 Version: 4.8.4300.0 built by: NET48REL1LAST_C
    CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/System/v4.0_4.0.0.0__b77a5c561934e089/System.dll

System.Drawing
    Assembly Version: 4.0.0.0
    Win32 Version: 4.8.4084.0 built by: NET48REL1
    CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/System.Drawing/v4.0_4.0.0.0__b03f5f7f11d50a3a/System.Drawing.dll

System.Configuration
    Assembly Version: 4.0.0.0
    Win32 Version: 4.8.4190.0 built by: NET48REL1LAST_B
    CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/System.Configuration/v4.0_4.0.0.0__b03f5f7f11d50a3a/System.Configuration.dll

System.Core
    Assembly Version: 4.0.0.0
    Win32 Version: 4.8.4320.0 built by: NET48REL1LAST_C
    CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/System.Core/v4.0_4.0.0.0__b77a5c561934e089/System.Core.dll

System.Xml
    Assembly Version: 4.0.0.0
    Win32 Version: 4.8.4084.0 built by: NET48REL1
    CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/System.Xml/v4.0_4.0.0.0__b77a5c561934e089/System.Xml.dll

************** JIT Debugging **************
To enable just-in-time (JIT) debugging, the .config file for this
application or computer (machine.config) must have the
jitDebugging value set in the system.windows.forms section.
The application must also be compiled with debugging
enabled.
For example:
<configuration>
    <system.windows.forms jitDebugging="true" />
</configuration>
When JIT debugging is enabled, any unhandled exception
will be sent to the JIT debugger registered on the computer
rather than be handled by this dialog box.

There were recently (Friday last) Windows 10 .NET framework updates, and before that as well. Is your Windows 10 machine completely up to date? 19042.789? — John, Feb 08 '21 at 17:24
What do the Details show per that error screen drop down? Have you checked your Event Viewer application and system logs to see if they show anything relevant? Also, are you actually click on an application or launching something to make that pop up the message or is it just popping up automatically? The error indicates it is looking for a server that is not found so curious to hear your detailed feedback for some of the things I've asked here @Niishaw — Vomit IT - Chunky Mess Style, Feb 08 '21 at 17:37
I updated my answer. It looks like this is malware. Please upload the file in question to https://virustotal.com and provide a link to the results. — Daniel B, Feb 13 '21 at 10:22

Daniel B · Answer 1 · 2021-02-13T10:18:52.573

This is a generic exception dialog that appears under certain circumstances when software running on .NET encounters an error the developers did not account for. It is not a problem with .NET Framework itself.

Here, it's about receiving a HTTP 404 Not Found response. This may simply mean a remote resource was moved away/became unavailable.

The relevant information is visible (and can be copied) when you click the details button. It could help identify the program responsible. You should update your question with this information.

Further information is also visible in Event Viewer in the "Application" log.

From the information you added, we can see that the program in question is located at file:///C:/Users/Niishaw/AppData/Roaming/EventLog/CheckUpdate.exe.

Unfortunately, this means you’re most likely dealing with malware. Please read this Q/A on how to proceed from here: How can I remove malicious spyware, malware, adware, viruses, trojans or rootkits from my PC?

.NET throwing strange errors on PC start up

1 Answers1