Seems to be a Seattle, WA land line. Provider is International Telcom, Ltd. Got these same IRS forms faxed twice on 12 Dec 2008 and 20 Dec 2008. I don't want to spend money paying for a reverse phone search, but it looks pretty much like phising. I live in Buenos Aires, Argentina, so finding out the name and full address of whoever is behind this scam would make little sense to me, but perhaps someone living in USA should do so.
In Chile we received a fax requesting information for IRS, FORM W-8BEN, they want all the information that you could give a swindler (maiden mother's name, passport copy, SSN, etc.)
I got this even in Bulgaria. Beware of phishing! Check with the IRS web site the form you are about to send, you will see that the actual IRS form is very different from the one you got by fax.
I'm glad there are sites like this. Got the form by fax. i'm in Bulgaria as well.... definitely a PHISHING SCAM!!! Look around the net, many examples of the scam, there are even word documents that you can "touch up" your self. However as someone already noted the original IRS form never asks about "bank accounts", bank and branch address, mother's maiden name etc. etc...