Anonymous hack Citigroup, Citibank Web sites

PanARMENIAN.Net - Hackers claiming to be members of the loose hacking collective Anonymous took credit for knocking the Citigroup and Citibank Web sites offline on Friday, February 3. At times the sites were only sporadically available, and some attempts to log into banking accounts were met with an error message, The New York Times reported.

Andrew Brent, a Citigroup spokesman, confirmed that Citigroup’s consumer site had experienced a temporary outage but said that Citigroup had been able to restore Web site operations within one hour and was continuing to monitor its systems.

This was part of a string of attacks this week by hackers who call themselves Anonymous Brasil. In posts on Twitter, the hackers said their attacks were intended to fight corruption. By Friday, they had at various times taken down the Web sites of Banco BMG, Banco Bradesco, Banco de Brasil, Banco Panamericano, Citigroup, HSBC Holdings, Itau Unibanco Banco Multiplo and Febraban, Brazil’s banking federation.

There was no evidence hackers had compromised any customer accounts in the attacks. They were able to take down the sites with denial of service attacks, which involve flooding them with traffic until they crash.

Denial of service attacks, while not technically sophisticated, can be difficult to thwart. Once attacked, a target can employ technologies to filter out false traffic, but that is only an after-the fact measure.

In the past, hackers affiliated with Anonymous have announced their targets before an attack. This was the case with PayPal and with Sony in March, when Anonymous attacked Sony’s PlayStation Network in retaliation for lawsuits against PlayStation hackers.

That at least gives targets an opportunity to step up defenses. The attacks on the Brazilian banks were not advertised beforehand. But in Twitter postings, hackers have said that they planned to target credit-card companies and government Web sites.