The attack began at approximately 10 a.m. on Sunday when traffic to one of Wikileak's primary hosting providers significantly jumped by two to four gigabytes per second, Craig Labovitz, chief scientist for security firm Arbor Networks, wrote in a blog post Monday.
A hacker calling himself "Jester" and using the Twitter handle “th3j35t3r" took credit for the attack, which made the Wikileaks site inaccessible for several hours.
In a tweet Sunday, the hacker said he took down the site "for attempting to endanger the lives of our troops and other assets."
Wikileaks announced the outage on Facebook and Twitter about 11 a.m. EST on Sunday but promised that the cables would still be released.
After the attack began, Wikileaks redirected DNS configurations from its Swedish hosting provider to sites hosted by Amazon's Elastic Cloud Computing (EC2) service in Ireland and later the United States, according to researchers. Despite the attack, Wikileaks began publishing the cables at cablegate.wikileaks.org on Sunday.
Prior to being published, some of the cables were released to several news organizations.
Among the 251,287 cables, which date from 1966 to the end of February, is one that describes a "global hacking effort" against Google, according to a report in the New York Times. The incident was first disclosed by Google in January when the search giant revealed that its systems, as well as those belonging to a number of other, high-profile companies, were compromised to steal intellectual property on behalf of Chinese hackers.
According to the Times report, the attack was ordered by China's Politburo, the governing force behind the ruling Communist Party.