Authorities are trying to find the source of a series of cyber attacks that have shut down online banking for thousands of Americans.
There are reports that the attacks could be the work of hackers in the Middle East.
The attacks hit Bank of America, PNC Bank and Wells Fargo this week and potentially threatened activities for millions of customers.
"There is an elevated level of threat. The threat is now high," Dough Johnson, vice president of the American Bankers Association, said.
"This is twice as large as any flood we have ever seen," former national security official Richard Clarke added.
Suspected hackers in the Middle East secretly took over computers across the globe, then the so-called "zombie computers" flooded the bank websites with traffic, effectively halting online banking for hours.
"The threats are getting increasingly sophisticated," Johnson said.
One group, called the Izz Adin al Qassam Brigades, sent a warning that said it would retaliate for the controversial "Innocence of Muslims" film about Mohammad that sparked recent rioting across the Muslim world.
CBN News has reported on the al Qassam Brigades based in Gaza and affiliated with Hamas. But some analysts believe a Middle Eastern government may be helping the hackers.
"This is the first time that we know about where a Middle Eastern entity, perhaps a Middle Eastern government, has attacked websites, critical infrastructure in the United States," Clarke claimed.
The cyber terrorists may be blaming the anti-Islam film, but it's clear that Islamist groups have been planning attacks like this for a long time. And security experts say the threat could grow if the groups are able to get into accounts or disrupt financial markets.
"If they get inside the banks," Clarke explained, "They can move money around and cause financial chaos."