MasterCard SecureCode service impacted in attacks over WikiLeaks

The attacks against MasterCard by WikiLeaks supporters that knocked the credit card company's Web site offline today may have caused more problems than previously thought.

MasterCard itself has so far said publicly only that its corporate Web site experienced availability issues as a result of a sustained distributed denial of service (DDoS) attack against the site. In a statement this afternoon, the company said that it was making progress addressing the issue and that no customer transactions had been affected.

It now appears that the company's Securecode service for secure online transactions was also affected. It's not clear, however, whether the SecureCode problems were caused by Anonymous, the group that knocked MasterCard's corporate site offline after the attacks began about 4 a.m. ET.

In multiple bulletins to transaction processing companies , the company said that MasterCard and Maestro transactions could not be processed via SecureCode because of a service disruption to the MasterCard Directory Server.

The server has been since failed over to a secondary site, but customers could still experience intermittent connectivity issues, MasterCard said. It did not offer a timetable for when it hopes to restore full service.

A MasterCard spokeswoman confirmed the disruptions to the SecureCode service, but insisted that online transactions had not been affected. Instead, there were "isolated reports" of SecureCode service slowdowns reported, she said, adding that SecureCode service has been restored to normal.

Meanwhile MasterCard rival Visa, which has also been under a DDoS attack, was finally knocked offline this afternoon. Visa's main corporate site appears to have been hit by two separate attacks according to Sean-Paul Correll, a researcher with PandaLabs. Correll has been maintaining a regularly updated blog on the unfolding attacks.

The first attacks against the site started last night after midnight ET and resulted in intermittent service disruptions for several hours. No group has so far claimed responsibility for those attacks, Correll said.

Then at about 4 p.m. ET today, the company was hit with another DDoS attack -- this time by Anonymous, the group of loosely affiliated hackers that has vowed to attack organizations seen as attempting to censor WikiLeaks.

In a statement, Visa said that its corporate Web site Visa.com was "currently experiencing heavier than normal traffic" and said it hoped to restore full site operations in the next few hours. "Visa's processing network, which handles cardholder transactions, is functioning normally and cardholders can continue to use their cards as they routinely would. Account data is not at risk."

Anonymous, which has also been attacking entertainment industry sites over copyright enforcement issues, this week launched Operation: Avenge Assange. It is targeted at "entities involved in censoring [WikiLeaks'] information."

So far, the group is believed to have been behind the attacks on MasterCard, Visa, Swiss payment transaction firm PostFinance , PayPal, EveryDNS and others. All of the targets recently announced plans to terminate service for WikiLeaks after the site began releasing confidential U.S. State Department cables.

In addition to these attacks, Anonymous has also launched attackes on the Web sites of Sen. Joseph Lieberman (I-Conn.), former Alaska Gov. Sarah Palin and the Web sites of the Swedish prosecutors who are pursuing rape charges against WikiLeaks founder Julian Assange.