This is the fake PC tech scam. See this thread:

 Jun 22nd, 2012
We received a call from this number recently. As per usual, while my spouse dealt with the phone, I immediately did an Internet search on the number showing on the Caller ID display on the TV screen (thank you Cox for that awesome feature). The display said the caller was Marsh & McLennan; my rapid-fire search quickly told me of how this company was located in floors 93-99 of one of the World Trade Center towers and no one there on 9/11/2001 got out. There's more but anyway, all of it was making alarm bells go off all over the place, and I started giving negative signs to my husband (a police officer who happens to have a Bachelor's degree in computer networking).

The man on the phone with a very thick Indian accent said our computer had a virus and he needed to have us do some things to it while talking to us over the phone. This stunk to high heaven. My husband said ok, we have multiple computers, so which one is it? (I'd just turned them all OFF because we didn't know who this guy was, or what he could possibly be doing from a remote location. Better safe than sorry at that point.) The man kept demanding that we sit at the computer and have it ON, but still no info on which one. Hubby said I'm not doing ANYTHING until you tell me what a MAC I.D. is! So the guy then read off our home address, which was a bit disturbing, but he obviously had no clue what a MAC I.D. was so he clearly had no idea about computers and this was obviously a scam. After several requests for our MAC I.D.s went unanswered, the guy got flustered and hung up.

We then called the number from the caller ID, supposedly to Marsh & McLennan. A recording said the number is known to be spoofed in Canada and has been reported to the authorities, and if we have been a victim of it then to call Phonebusters. (Ppl in the US can also talk to them as well, and we can talk to our own Dept of Commerce. They need to be aware of & have a record of this growing problem/scam.)
 Jun 13th, 2012
Very thick accent and telling me I had cable. When I told him I had Dish TV he hung up.
 May 29th, 2008
It's a scam thing thats going around. I called the number back today and theres a message to call Phone Busters to report them.
 May 28th, 2008
Keeps calling my number. I'm getting angry. So I pick up the phone and hit #####
 Apr 24th, 2008
Last night received a call from this number and the caller hung up when I said hello. Today received the call and when I answered an East Indian guy was on the other end trying to sell me long distance through Primus Canada. I politely said I wasn't interested and the man became quite rude with me so I just hung up.
 Apr 09th, 2008
Just like SFarmer reports.....
 Mar 12th, 2008
Repeated calls from different states but always the same 345-6789 #. Rings until voice mail picks up but leaves no message.
 Jan 17th, 2008