Visa.com has been taken down by a distributed denial of service attack carried out by WikiLeaks supporters. Despite having its own website suspended, Operation Payback successfully managed to take down Visa.com by reconfiguring its existing LOIC botnet to attack the new target.

Operation Payback successfully took out MasterCard.com earlier today, using only 400 LOIC clients when the site first went down. Even though Visa.com generally receives fewer visitors than MasterCard.com, it is hosted on the Akamai content distribution network. It was therefore regarded as a more difficult target, so the hacktivist group waited until they had more than 2000 active LOIC clients before commencing the latest attack against Visa.

The attack appears to have succeeded – Visa.com was taken down almost immediately and remains inaccessible for many of its visitors.

Real-time performance graphs for www.visa.com can be viewed here. Several other sites involved in the WikiLeaks attacks can also be monitored at http://uptime.netcraft.com/perf/reports/performance/wikileaks