The plot to steal information on 100,000 taxpayers from the Internal Revenue Service and hijack nearly $50 million in refunds not only reveals a previous security breach but hints at a wider fraud that may bedevil Americans in the future.

Some security and tax experts warned that this latest data theft might be a prelude to more targeted schemes aimed at duping taxpayers into handing millions of dollars over to criminals or to help thieves circumvent the agency’s security filters next year and beyond.

“This breach is not just about what this single group is going to do with the information, but what happens when this information gets sold on the black market,” said Peter Warren Singer, the author of “Cybersecurity and Cyberwar: What Everyone Needs to Know.” “It’s rare for the actual attackers to turn the information directly into money. They’re stealing the data and selling it off to other people.”

It is almost impossible to find a business or government agency that has not had some kind of security breach, he noted. Millions of customers at companies like Target and the private insurer Anthem have had data compromised. And this year, TurboTax temporarily halted electronic filing of state income tax returns after seeing an uptick in attempts to use stolen information to file fraudulent returns and wrongly claim tax refunds.