The number is spoofed, the caller is overseas probably in India or Pakistan.
IRS Scam:
The IRS does not need to sue anyone. They send you first class letters delivered by the Post Office. Several of them. Ignore those, and they then send certified letters that you need to sign for. Again delivered by the Post Office. Ignore those and they simply freeze your bank accounts and anything else you own. If they can do that, then why would they bother with a court case that might take them years before they get in front of a judge?
Official IRS Government site detailing this scam and providing links to report it:
http://www.irs.gov/uac/Newsroom/IRS-Warns-of-Pervasive-Telephone-Scam
If you feel you SSN has been compromised, in addition to putting a fraud alert at the 3 credit bureaus, you may want to notify the IRS. Here is the link, fill out the proper form (probably 14039):
http://www.irs.gov/Individuals/How-Do-You-Rep ... aud-Activity%3F
Left a voicemail saying I was being sued. A robotic voice of some girl from India. So shady. I have been audited by the IRS, they send you a letter via the US Postal service. Your mailman/woman would be the one to deliver such news to you if it was the actual IRS. This is a scam, hang up, and report.