Hackers are trying to steal our tax refunds -- again

If hackers have it their way, you may not be getting that tax refund from the IRS.

Online thieves were recently able to get their hands on taxpayer identification numbers before the Internal Revenue Service detected the attack and shut it down, the agency revealed Tuesday. The "Electronic Filing PINs," meant to ensure information is safe, would enable hackers to file fraudulent tax returns.

As the number of tax returns being filed online has continued to rise -- it's expected to be 80 percent of the 150 million returns filed this season -- so too has the number of attempts by hackers to file fake returns and steal people's refunds.

The attack revealed Tuesday involved specialized software that used more than 450,000 stolen Social Security numbers to try to generate e-filing PINs. Attempts involving about 100,000 of those SSNs were successful, the IRS said in a statement.

The SSNs were "stolen elsewhere outside the IRS," the agency said, adding that "no personal taxpayer data was compromised or disclosed" by its systems. The agency said it will notify people affected by the attack and will mark their accounts to guard against identity theft.

It's not surprising that hackers find tax returns tempting. After all, the documents have your income, birth date, home address, family details and SSN written right on them. Such information can be used not just to steal your tax dollars, but also to break into other systems, like your bank, credit card or social-networking accounts.

Is one of your security questions your mother's maiden name? Hacks could glean that name from your family's tax returns.