Banks are no strangers to cyber assaults on the sites customers use to access accounts, and it appears JPMorgan Chase was the most recent victim of such an attack yesterday. The bank said last night it was working to restore normal service after an unspecified amount of down time during the day.

Some users couldn’t access their accounts or had a slower time of it because of a denial-of-service cyber attack, reports Reuters. Other banks like Citigroup and Bank of America have had a rough go of it recently as well, warning investors that cyber attacks could continue.

Reuters says it attempted to access Chase.com yesterday and were notified that the site was down, but it did work this morning for yours truly.

It’s not just this one isolated incident — intelligence officials said yesterday that cyber attacks and cyber spying are a bigger security threat than terrorism for the U.S.

The Director of National Intelligence testified as such during an annual “worldwide threat” briefing recently, while the head of the U.S. military’s Cyber Command said in another hearing that cyber attacks on major companies, especially big U.S. banks, are getting worse.

Bank in September, hackers claimed they mucked up Bank of America’s site because of a reportedly anti-Islam movie, while Wells Fargo had problems with its site in December for about four days.

There’s likely no threat to user information (at least none that has been reported by Chase), as denial-of-service attacks work by deluging Web sites with a high amount of traffic, causing them to simply shut down.

Cyber attack stops access to JPMorgan Chase site [Reuters]

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