The wave of cyberattacks that hit US banks in September was the work of Iran, according to a US government official.
The DDoS attacks - which are still continuing - have targeted around a dozen banks, including Wells Fargo, the Bank of America, JPMorgan Chase and Citigroup. While there were suggestions at the time that the attacks might be a response to an anti-Islam movie clip posted on the internet, many security experts suspected Iran at the time.
A group called the Izz ad-Din al-Qassam Cyber Fighters later claimed responsibility, but is now believed to be controlled by the Iranian government.
"There is no doubt within the US government that Iran is behind these attacks," James A Lewis, a former official in the State and Commerce Departments and a computer security expert at the Center for Strategic and International Studies in Washington, tells the New York Times.
According to the US, Iran is carrying out the attacks in response to Western sanctions - and for the Flame, Duqu and Stuxnet viruses that have hit Iranian computers and infrastructure over the last couple of years.
The reason the US is so certain about the origin of the attacks is their sheer volume, with the hackers targeting data centers, as well as the fact that it's been impossible to trace the attacks back to any command and control center.
In a post on Pastebin yesterday, the Qassam Cyber Fighters reiterated that the attack was prompted by the Innocence of Muslims video, and claimed that their campaign was working.
"Cyber-attacks of al-Qassam CF in recent weeks showed that despite the high cost of US banks to deal with these attacks, the attacks cannot go under control and are unstoppable," they say.
"Dissatisfaction of customers of the banking services is increasing, but, by contrast, the banks responsibility about the disruptions of their activities is reducing day by day."