The scope of a 2015 IRS data breach has been found to be much larger than originally suspected, with more than 700,000 Social Security numbers stolen, according to a CBS News report.
The hackers behind the attack targeted the "Get Transcript" program, which allows taxpayers to check their tax history online, according to the report.
In May 2015, the IRS announced 114,000 taxpayers were affected. The estimate of affected people rose to 334,000 three months later. Now, the latest disclosure ups the number to 724,000, according to the report.
The IRS will be informing the cyberattack victims via mail, as well as offering a free year of identity protection.