Avoiding tax software will not prevent your refund from being stolen, and neither will anything else, say security and tax experts.

"There's really nothing you can do to protect yourself. It's depressing," said fraud expert Avivah Litan, vice president and analyst for Gartner Research. "This is the type of fraud I worry about."

The Federal Bureau of Investigation is investigating how fraudulent returns were filed in 19 states through TurboTax software, the Wall Street Journal reported on Wednesday. TurboTax maker Intuit Inc temporarily stopped transmitting state returns last week after noticing attempts to use fraudulent identification information.

The company said it does not believe the fraud resulted from a security breach of its systems and that the stolen information must have come from another source.

"Intuit has not been notified, nor are we aware, that we are the target of an FBI investigation," Intuit spokeswoman Julie Miller said in an email to Reuters.

With all the recent database breaches and hacks, there are plenty of sources for all the information that thieves would need to create bogus tax returns and steal people's refunds, Litan said. Social Security numbers, answers to security challenge questions and other private information on millions of people is up for grabs.

"We know that these have been stolen and sold," Litan said. Court Ventures, a public records aggregator now owned by Experian, unwittingly sold information to identity thieves from a database containing more than 200 million records that included Social Security numbers. Another 80 million customers and employees had their Social Security numbers and other private information exposed in the recent breach of health insurer Anthem Inc. Hackers are also targeting accounting and law firms to mine personal information, Litan said.

Once thieves have a Social Security number, creating phony W-2s is not that hard, she said: "You can get everything you need from LinkedIn and Facebook."

The IRS paid $5.2 billion in fraudulent tax refunds during the 2013 tax season while preventing another $24.2 billion from being paid, according to the U.S. Government Accountability Office.

Victims often wait months and sometimes even years to have their refunds restored, said tax preparer Laurie Ziegler of Saukville, Wisconsin, who has helped people victimized by refund fraud. Cuts in IRS funding and staff levels mean victims are likely to wait even longer this year, she said.