IRS targeted in bot attack

Data thieves used an automated attack technique and stolen Social Security numbers to try to establish accounts with IRS systems, the tax agency disclosed late on Feb. 9.

The attack was designed to generate e-filing PINs, which would presumably be used to request fraudulent tax refunds.

The IRS said attackers deployed two key weapons: an automated bot and stolen Social Security numbers they'd obtained elsewhere.

"With our improved systems, we were able to catch it quickly," IRS Commissioner John Koskinen told the Senate Finance Committee on Feb. 10. He compared the attack to last year's compromise of the Get Transcript app.

"None of those attacks breached our system itself," Koskinen said, noting that in both instances, hackers already had personal information on targeted taxpayers.

In a statement on the latest attack, the IRS said, "No personal taxpayer data was compromised or disclosed by IRS systems." Officials plan to notify affected taxpayers via mail and will monitor their accounts for future identity theft attempts.

Attackers used roughly 464,000 Social Security numbers in the latest attack.

Koskinen blamed global organized crime syndicates and noted that the attackers "hopped" from country to country as the IRS detected and attempted to halt the activity. Officials are investigating the incident but believe that the attack has been stopped.

They said it is not related to last week's hardware failure at the IRS.