I also had a call 2 times from the number and I just did not argue with them and hang up. They are now trying to phone people in Malta, therefore be careful, do not do anything with your computer just hang up.

Called today saying computer infected, my wife handed off to me and he hung up on my questioning.

I got a call from this number.  The man said he was from the National Computer Co and my computer was in danger.  The motherboard had been inffected and I could lose all my data.   I needed to do exactly what he told me to do to save my data.  I hung up.

Received a call from a man with an Indian accent.  He knew my first name and said he was calling about my computer.  I said "no thank you" and hung up.
Never seen a number with the prefix 4-905.

Rec'd a phone call from a man with an India accent at 3:52pm on May 30th. The number showing on my home was 4-(905) 512-3123. Said that I had downloaded a virus on to my MY COMPUTER Windows #7. Said if I would open my computer he would show me. I ASKED HIM TO CALL BACK IN 5 MINS. In the mean time I called Dell Support