Cyberattacks were carried out over the past two days against Visa, MasterCard, and the Swedish Prosecution Authority—all institutions that have taken action against Wikileaks—in a campaign called “Operation Payback” by hackers.
The attacks are linked to the arrest of WikiLeaks’ founder Julian Assange in London on Tuesday.
The hacker group AnonOps took responsibility for the attacks. “Hackers Take Down Visa.com in the Name of Wikileaks. Wow. This is getting crazy,” read a Twitter message on the feed for Operation Payback.
The Swedish Prosecution Authority, the body that issued a European arrest warrant for Assange on suspicion of sexual crimes, was attacked Tuesday evening, the Authority confirmed in a statement now posted on its restored website.
“Due to an unusual amount of visitors the site became overloaded and eventually was closed down. The site was restored on Wednesday morning.
“The Internet supplier of the prosecution authority has confirmed that it was a deliberate attack. The incident has been reported to the Police.”
As of 4 p.m. EST Wednesday, Visa's website was still down. The hackers used the same tactic described above of flooding the site with data causing it to shut down, called a distributed denial-of-service (DDoS) attack.
At first, the hackers apparently targeted the wrong Visa website. It was Visa Europe that announced on Monday it would temporarily suspend payments to Wikileaks, not Visa inc.
“Visa Europe is a separate company to Visa inc. and we have different websites,” said Amanda Kamin, spokesperson for Visa Europe.
“The visaeurope.com is functioning,” she said. But 30 minutes later also the Visa Europe website went down.
Wednesday MasterCard was also down for several hours in a related attack. On Monday, Mastercard had announced it would stop processing donations to the Wikileaks organization.
As of 3:35 p.m., the website was up albeit slow. According to Mastercard, credit card transactions were not usurped in the process.
DataCell EHF, an Iceland based company that processes donations to Wikileaks said n Wednesday that they plan to take legal actions against Visa and Mastercard over the suspension of payments.
“We strongly believe a world class company such as Visa should not get involved by politics and just simply do their business where they are good at—Transferring money,” the company said in a statement.
Wikileaks in the meantime continues with its release of classified U.S. diplomatic cables on its website. On Wednesday the organization published 52 new cables, totaling 1,112 at present.
“The release of the U.S. Embassy Cables—the biggest leak in history—will still continue,” said Kristinn Hrafnsson, spokesperson for Wikileaks in a statement on Wednesday.
“We will not be gagged, either by judicial action or corporate censorship,” he said.