Spurious Keystrokes

[liceboy]

My Dell laptop (Win XP Pro) has been behaving erratically: pop-ups of various kinds closing before they can be read, windows opening behind the window they are opened from, jumping around unpredictably in dialog boxes and so on.

Suspecting spurious mouse or keyboard events I knocked up a little program and discovered that the machine is continuously generating a phantom keystroke at the precise rate of 1 per second. It's generating an ASCII 255 character which is not in itself visible, but the phantom keystroke is the cause of all the weird symptoms.

Hardware problem, maybe?

 

[BadBigBen]

Possible, but more likely a malware problem...

I would do a complete AntiViral scan, AntiMalware scan with several tools...

Trendmicro Housecall (online viral scanner)

http://housecall65.trendmicro.com/

Malware scanners:

Spybot S&D

http://www.safer-networking.org/en/index.html

AVG Antimalware (Trial) - Ex EWIDO...

http://www.ewido.net/en/download/

also you may want to do a HiJackThis scan and post the log here for our perusing...

http://www.trendsecure.com/portal/en-US/tools/security_tools/hijackthis

Ben

"If it works don't fix it! If it doesn't use a sledgehammer..."

 

[wahnula]

Trendmicro's HouseCall is also an excelent service. Gogle "Housecall".

Tony

"Buy what you like, or you'll be forced to like what you buy"...me

 

[liceboy]

Hi there,

Thanks for replying. I hadn't considered malware because I regularly scan the computer with AVG Anti-spyware and Lavasoft Ad-aware. Also, the probem still occurs in safe mode. OTOH, the precise timing of once per second doesn't seem terribly likely for a hardware fault. I will try the additional products you both suggest, and also come back here with the Hijack This log. I hope this turns up something, 'cos if it's a hardware prob I'm gonna have to send it back to Dell (still under warranty).

Thanks again.

Baz

 

[paparazi]

Sorry to have to disagree, I'm not saying that it couldn't be a virus of some sort but this problem is more likely due to a faulty keyboard.
Over the years I've seen seven or eight laptops of different brands with exactly these symptoms and all were repaired with a keyboard replacement.
Keyboards generally are either sealed or too dificult to strip and rebuild but I have sucessfully reaired a couple.
I shouldn't hold out too much hope of repairing (actually mostly cleaning) yours but it may be worth a try before ordering a new replacement.
Martin

We like members to GIVE and not just TAKE.
Participate and help others.

 

[liceboy]

Hi Martin

I suspect you are right, someone with previous experience of this symptom is what I hoped to find, so thank you. I'm throwing a huge battery of anti-malware resources at it, but nothing has been found yet. This doesn't surprise me really: it's my development machine, I don't use it for playing, I don't download anything except technical software and updates, I don't even surf with it except for technical resources, and it lives behind a tight firewall, so I don't really see how it could have got infected.

It being still under warranty, replacing the keyboard will be Dell's problem. Unfortunately I will be without it while they fix it. Luckily I decided to keep my old dev laptop!

Thanks

Baz

 

[acewarlock]

They will not repair it, they will just send you a new one. So if you want the info on the HD, you better back it up or better yet, remove the HD and keep it safe.


This is a Signature and not part of the answer, it appears on every reply.

This is an Analogy so don't take it personally as some have.

Why change the engine if all you need is to change the spark plugs.

 

[liceboy]

Maybe so, although a customer of mine recently sent back a new Dell with a faulty motherboard and they did actually replace the motherboard and return the same machine.

But I can't send them my confidential customer data anyway (especially if they are just gonna chuck it in a skip where anyone could liberate the HD!) so it will all have to be backed up and properly erased before I return it. Or, when I call them on Monday I will check if they are happy for me to remove the HD (i.e. that they will not then say that I have invalidated the warranty!)

Thanks

Baz

 

[jjjthird]

I replaced many of Dell's keybds on laptops, especially D600

 

[kmcferrin]

I agree that it's most likely faulty hardware, but I just had to comment on this:

This doesn't surprise me really: it's my development machine, I don't use it for playing, I don't download anything except technical software and updates, I don't even surf with it except for technical resources, and it lives behind a tight firewall, so I don't really see how it could have got infected.

Just because the PC is behind a firewall and used only for known good sites/applications doesn't necessarily mean that it's safe. It's entirely possible that another PC or resource behind your firewall isn't so well protected, and could be used as a platform to attack any other systems.

 

[liceboy]

Hi jjthird,

Thanks for your reply. If it wasn't under warranty I would happily replace the keyboard myself. I've pulled Dell laptops apart to replace various parts in the past, even once a backlight tube, I'm sure replacing a keyboard has to be pretty easy. However, the earlier poster was, I think, referring to the probable difficulty of repairing the keyboard, rather than replacing it. But, it is under warranty, so Dell can sort it out.

Baz

 

[liceboy]

Hi kmcferrin,

I didn't say that it *couldn't* have been attacked, merely that I would be surprised if it had been (and indeed I am now quite sure that it hasn't been). Obviously there is no such thing as a 100% guaranteed secure network or system but this one is, IMNSHO, pretty well secured (having done it all myself)!

Baz

 

[liceboy]

Hi all,

Martin was spot on about it being a keyboard fault. On Dell's instructions I removed the keyboard (very easy), and with only an external keyboard connected there are no spurious keypresses. Dell is sending a new keyboard, so I don't need to mess around erasing data and sending the computer back.

Thanks all for help and suggestions.

Baz

 

[BadBigBen]

Glad you got it sorted...

and glad my theory was wrong...

Ben

"If it works don't fix it! If it doesn't use a sledgehammer..."