By ALAN RAPPEPORTAPRIL 6, 2017
WASHINGTON — The Internal Revenue Service said on Thursday
that the personal data of as many as 100,000 taxpayers could have been compromised through a scheme in which hackers posed as students using an online tool to apply for financial aid.
The commissioner, who in the past has faced calls from many Republican lawmakers to resign, said
that the agency had already sent out 35,000 letters to taxpayers and that it was planning to contact 100,000 people to alert them that they might be at risk.
The breach may be the most extensive since 2015, when thieves gained access to the tax returns
of over 300,000 people by using stolen data and filed fraudulent returns to get refunds.
“Where I come from,” he said, “if you sign up for a commitment, you complete that commitment.”
A version of this article appears in print on April 7, 2017, on Page A21 of the New York edition with the headline: I. R.S.
The agency became concerned last fall when it realized
that it was possible for criminals to take advantage of the student loan tool that allows aid applicants to automatically populate the applications with their and their parents’ tax information.
Mr. Koskinen said he did not want to cut off a tool that millions of financial aid applicants use before the evidence of foul play was clear.