CPU usage shoots to 100% when IDLE

[compnovice]

Whenever, I stop using my laptop and leave it idle, the processor becomes really hot and the fan starts. As soon as I start the Windows Task Manager by pressing ctrl+alt+del the CPU usage drops from high 80-100% to 1-5% and functions normally.

To see if my computer was being used as a dummy to relay over the internet by some spyware, I disabled my internet connection but the problem persisted. I do have Limewire (disabled on startup), but the problem persists even when I am not connected to the internet. So, I would rule out some malacious program accessing the internet.

I am using XP Home, with Athlon XP-M 2200+ processor with 512 MB memory. I use McAfee AV, E-Z Armor Firewall and loads of anti-spywares regularly ( Spybot, Ad-Aware, Spyware Doctor, MS-antispyware and Ewido Security suite).

MS Anti-spyware, McAfee AV, E-Z Armor Firewall and Google Desktop are allowed to "always run" in the background. Other anti-spywares and windows firewall are disabled unless used manually

I defragment all my partitioned drives regularly.

I know wireless cards may use a lot of memory trying to find available wireless networks, but disconnecting it too does not make a difference.

I do not have SETI style programs on my laptop.

I cannot find the processes causing 100% usage because as soon as I start the Windows task manager I can see the usage drop from 100% to 1%. I can see the spike in the graph but am not able to capture the processes on the spike. However, sometimes I do see large number of svchost.exe files when the usage jumps to 100%(even when I am not using memory intensive programs). But the maximum usage is either by firefox or explorer.exe (not IE).

Can someone tell me why the CPU usage shoots up to 100% when my laptop is idle?

Thanks in advance.

 

[ProviaFan]

This sounds like a program that is detecting when the task manager is run and chilling out at that time... I would suggest making a copy of \WINDOWS\SYSTEM32\taskmgr.exe onto your desktop, and renaming it to something else (asdf.exe or whatever suits you). Try running it then to see if you can catch whatever's hiding when the "real" taskmgr.exe is running.

 

[The Pentium Guy]

Spyware?

 

[Red Squirrel]

Sounds like spyware to me too, or a virus that got past mcafee.

 

[imported_michaelpatrick33]

Originally posted by: The Pentium Guy
Spyware?

You still have my quote/rants in your sig, pentiumguy?

It does sound like spyware or a background program running when the computer is idle, but it is odd that it drops so much when task manager is opened. It is like it is disguising itself like a previous poster talked about.

 

[akugami]

I'd run ad-aware and spybot, then install something like netlimiter that can monitor what programs are accessing the internet. Also try using http://www.sysinternals.com/Utilities/ProcessExplorer.html to see what's running. Do a google search for suspicious items.

 

[KoolDrew]

Originally posted by: RedSquirrel
Sounds like spyware to me too, or a virus that got past mcafee.

 

[compnovice]

I already use the latest versions of Spybot, Ad-Aware, Spyware Doctor, MS-antispyware and Ewido Security suite. Are there better antispywares which could help me locate the malicious program?

Originally posted by: ProviaFan
This sounds like a program that is detecting when the task manager is run and chilling out at that time... I would suggest making a copy of \WINDOWS\SYSTEM32\taskmgr.exe onto your desktop, and renaming it to something else (asdf.exe or whatever suits you). Try running it then to see if you can catch whatever's hiding when the "real" taskmgr.exe is running.

That was an interesting approach... I made a copy of taskmgr and ran it after the system was idle for 5 min. But as soon as I launched it the same thing happened and the CPU usage dropped from 100% to 2%. Probably the spyware (or whatever it is) detects keystrokes?

 

[compnovice]

Another, thing I tried:

I left my Task Manager window open and left the laptop idle. There was no spike in activity.
However, I closed the task manager and left the computer idle. Then after around 20 min the processor became hot and the fan switched on. When I opened the Task Manager I could see the usage drop from 100% to 1-2%.

And, I have absolutely no idea why this is happening

 

[ProviaFan]

Here's an online virus scan for another perspective. Also, does the Google desktop thing index your files for searching or something? Maybe that's what's working in the background when the system is idle...

 

[stevty2889]

Have you tried opening task manager, and then letting it sit idle for a bit to see if it happens again?

 

[ProviaFan]

Originally posted by: stevty2889
Have you tried opening task manager, and then letting it sit idle for a bit to see if it happens again?

Read two posts above yours...

 

[compnovice]

Originally posted by: ProviaFan
Here's an online virus scan for another perspective. Also, does the Google desktop thing index your files for searching or something? Maybe that's what's working in the background when the system is idle...

I have disabled Google Desktop to run in the background (though not recommended by google) for the past few days but I still get the 100% usage when idle. I will check out the Online anti-virus. Thank you.

 

[stevty2889]

Originally posted by: ProviaFan

Originally posted by: stevty2889
Have you tried opening task manager, and then letting it sit idle for a bit to see if it happens again?

Read two posts above yours...

Oops, missed that..

 

[Vikesrock]

I would try downloading HijackThis and posting the log on a forum like TechSupportForums.com or Spyware Warrior

 

[classy]

A quick way to check what's going on is by going to a command prompt and check connections with netstat. If its spyware running when you go to idle it will have established a connection. Try that.

 

[akugami]

Try putting a copy of the taskmanager in the startup folder, this way you won't need keystrokes to open it. Leave it and see if you can catch what is sucking up 100% CPU.

Thought of something else, don't wanna make you sound stupid but you checked to make sure it's not a screensaver right?

 

[compnovice]

Originally posted by: akugami
Try putting a copy of the taskmanager in the startup folder, this way you won't need keystrokes to open it. Leave it and see if you can catch what is sucking up 100% CPU.

Thought of something else, don't wanna make you sound stupid but you checked to make sure it's not a screensaver right?

To be honest, I did not think about the screensaver :shocked: But, my screensaver starts after 30 min of the laptop being idle and the cpu usage spikes up well before that...

I have removed Google Desktop and Limewire.. The spike is now less frequent, but it still does occur...

I will put the taskmanager in the start-up menu and check..Thanks

 

[compnovice]

Originally posted by: classy
A quick way to check what's going on is by going to a command prompt and check connections with netstat. If its spyware running when you go to idle it will have established a connection. Try that.

I tried checking the connections after leaving the laptop to idle... It does not give any program trying to connect to the internet... Earlier I had removed my wireless card, but that also did not help

 

[compnovice]

Originally posted by: Vikesrock
I would try downloading HijackThis and posting the log on a forum like TechSupportForums.com or Spyware Warrior

Thanks Vikesrock...I will try that too...

 

[Green Man]

I just wanted to mention that it is normal to see a CPU spike to 100% and then fall to near 0% when task manager is opened. I hope you're not chasing a red herring.

Also, have you tried adding the CPU Time counter in to Task Manager? It will show total CPU time of all processes listed since you last booted. Unfortunately, it still won't show processes that ended or are hidden, but it's worth a shot.