Iran is a logical suspect in a barrage of cyberattacks that have hit major US and international banks in recent months.

The so-called distributed denial of service attacks (DDoS) – which make it hard to access websites that are being bombarded with requests from hacker-run computers – seem understandable for two reasons: They could be revenge for the computer viruses such as Stuxnet that destroyed more than 1,000 Iranian centrifuges in 2010 and other covert assaults on Iran’s nuclear program. They could also be a response to draconian US-led sanctions on Iranian banks that are making it difficult for Iran to conduct normal trade and especially to repatriate money from oil exports.

Cyber experts who have spoken to US officials say they are convinced that the culprit is a government  and that that government is Iran’s. But neither the Treasury Department nor the White House would confirm this — just as the Barack Obama administration declines to comment on allegations about its own covert warfare against Iran’s nuclear activities.

Jason Healey, director of the Cyber Statecraft Initiative of the Atlantic Council, a Washington think tank, told Al-Monitor that “the attacks by Iran on the US finance sector have been one of the most serious cyber conflicts. The DDoS attacks have been far, far larger than any than have ever been seen, much more severe than any organization could easily defend itself against, like trying to channel a tsunami through a normal water pipe.”