Alright lets see if we can solve this:
The a.exe is showing up in your hijackthis log:
- C:\WINDOWS\system32\a.exe?
Have you tried removing it from the hijackthis log along with browsing to the c:\windows\system32 directory and deleting the file from there.
Also check your startup menu to see whether there is anything in there that is loading it.
You can also open "regedit" and browse to the following location : HKEY_LOCAL_MACHINE - SOFTWARE - MICROSOFT - WINDOWS - CURRENTVERSION - RUN
and see whether there is anything relating to a.exe within there.
The virus it relates to is - W32.Ahlem.A@mm
This is from symantec website
Click Start, and then click Run. (The Run dialog box appears.) [*]Type regedit [*]Then click OK. (The Registry Editor opens.)
Navigate to the key:
[*]HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\Curr entVersion\Run
In the right pane, delete the value:
[*]"SYSTEMSars32"="%windir%\csrss.exe"
Exit the Registry Editor.
Restart the computer
http://securityresponse.symantec.com...hlem.a@mm.html