IRS kills e-filing PINs prematurely due to cyberattacks. From Endgadget. The IRS was gearing up to kill e-file PINs later this year, but it has decidedto speed up its plans after discovering suspicious activity. These electronic filing personal identification numbers, which people could use to authenticate tax returns filed online, are no longer available on IRS.gov or via the agency’s toll-free phone number. If you’ll recall, identity thieves used malware to steal taxpayers’ info from other websites, which was then used to generate 100,000 PINs, back in February. The thieves were actually gunning for 464,000 PINs, but the agency was able to stop them before they got near that number.