Chase denies hacking in vanishing balances

Updated 10:47 p.m. ET

Chase Bank experienced technical difficulties for over an hour Monday night, worrying customers who logged into their accounts and saw their balance at $0 or were unable to get any access to them at all.

A spokesman for the bank said it was strictly an internal technical issue and customers' accounts were not in danger.

"The problems are an issue with the checking account portion of chase.com, nothing to do with mortgage or credit banking. We have a technology problem regarding customers balance information that we are working to resolve," the spokesman to CBS News. "It has nothing to do with cyber threats or hacks. It is an internal issue. We are very sorry to our customers for the inconvenience."

Within two hours, the bank tweeted that the issue was resolved. Customers reported seeing their balances once again.

Still, hundreds of Chase users expressed their frustration on Twitter and Facebook. Many reported seeing their account balances listed as "$0" on mobile devices, while others said they got a "System Unavail" message when logged into the bank's website on their computers.

The hacking collective "Anonymous" said they were responsible for the vanishing balances on Twitter, but there is no evidence supporting their claim.

As CNET's Steven Musil notes, the scare was only natural given that the disappearing balances occurred "less than a week after a massive distributed-denial-of-service attack rendered Chase's Web sites useless for many hours." In that case, customers trying to use chase.com's banking tools were greeted with a note that the site was "temporarily down."