I got a call from this site as well.  It is a scam, asking for remote access to your computer.  They will try to sell you anti-spam software that they likely don't even have, but what they're really trying to do is get access to your sensitive information.  

You are supplying folks with some of the most informative help on how to avoid being scammed that I have seen yet. It would also to helpful if you made mention that those who become enlightened by the information you refer them to, need to share this information with others, to help them to avoid becoming victims. I'm hoping people take time to read about the various scams--sometimes it's quite evident folks simply come here to complain, and do not even read suggestions posted by others. How many times do we see questions asked about the identity and motives of the callers, when that question has already been answered repeatedly. Keep it up--good work!

You may have been subjected to scam  #3 as described at
http://phonehelp.2truth.com/facts.html

That site also shows how other 800notes visitors have reduced the number of telephone scams and telemarketing calls they receive.  (And, a link to Amazon's phone blocker devices and apps is there).

This was the initial number that phoned me on February 28.  My caller ID reads "Colton, CA".  A gentleman with a very heavy Indian accent told me that they had been notified that my computer contained numerous viruses.  When I asked what company he was with, he told me that he was a Microsoft Certified Engineer.  I knew that this was a scam -- he kept prompting me to "press these keys".  They would have given him remote access to my computer.  I asked him if he was with Microsoft.  He said that he was a "Microsoft Certified Engineer."  Eventually, I hung up.  

I phoned them back thinking that it was simply a telemarketing company.  The phone was answered by this gentleman and indicated that it was some Computer Service Company.  I hung up.  The most recent two calls from Colton California were from the number 909-254-9999.  I just haven't been answering those.