One of my computers began acting differently about a year ago, nothing extraordinary but since it was a work computer I knew it like clockwork and something didn't feel right.

After getting a clean bill of health from all of the major anti-virus scanners and passing various tests I still felt like the computer wasn't right and so I tried some more extreme measures of finding problems and discovered a rootkit, namely a Sinowal virus.

As you know, these have stealth and re-infection capabilities and so cleaning it was difficult, formatting/replacing the hard drive isn't enough. Knowing what I was dealing with however, I managed to clean the system and that's when the phone calls started.

Within a week I received a call from a gentleman with a Russian accent claiming to be from Microsoft and wanting to help me clean the "many error messages we are receiving from your computer". Knowing that Microsoft would not hire a 3rd party company and reveal any of my information to them I politely declined.

Since then I receive about a call per month, though now from a call center somewhere in India, making the same claim. I no longer own the computer, it was dismantled and junked 4 months ago but since they don't know that they keep calling.

I don't know if they want to re-infect the computer or help erase any sign of their virus but the fact that they are using call centers to contact me leads me to believe this was/is a widespread problem so I figured I'd share this story.

- Microsoft will not call your home claiming to be receiving errors!

If you get a random call from someone claiming to work for Microsoft, don't reveal anything more than what is available in the phone book about yourself!

P.S. I know I'm not being randomly targeted by a con-artist trying to peddle security software because the callers have each mentioned something they would only have known if they had access to the computer at one time.