The IRS believes that criminals behind a major security breach that allowed them to access tax information from more than 100,000 U.S. households were based in Russia, sources confirmed to Fox News Wednesday.
A well-placed cyberintelligence source familiar with the investigation into the breach told Fox News that the attack, which breached the IRS system, originated out of Russia. Additionally, the IRS alerted the Department of Homeland Security following the breach, a federal law enforcement official said.
The agency said Tuesday that criminals had used stolen Social Security numbers and other data to gain unauthorized access to the accounts. They then used the information from prior years’ returns to help them file for fake refunds using a system called “Get Transcript,” for which they had to clear a security screen that required knowledge about the taxpayer, including Social Security number, date of birth, tax filing status and street address.
The IRS said thieves targeted the system from February to mid-May. The service has been temporarily shut down.
Read More: IRS believes cyberattack originated in Russia, sources say | Fox News