Turkish banks fend off cyberattacks, some transactions hit

A number of Turkish banks reported serious disruption in online operations and credit card transactions Dec. 25, as hackers stepped up a series of cyberattacks seen in the country over the past week.

Officials at several Turkish banks including I? Bank, Garanti and state lender Ziraat Bank confirmed the attacks, saying they had caused intermittent disruption, Reuters reported. Bank shares were unmoved by the news. 

"The attacks are serious," said Onur Oz, a spokesman for Internet provider Turk Telekom. "But the target is not Turk Telekom. Instead, banks and public institutions are under heavy attack," he said. 

"A majority of Turkish institutions use Turk Telekom as the service provider, therefore we are the ones doing the defense against these attacks." 

Some 50,000 computers in Turkey unintentionally contributed to attacks without the knowledge of their owners, according to experts who commented on the attacks that intensified on banks for two days. 
The technique used by Anonymous, the alleged hacker group behind the cyberattack, is known as a Denial of Service Attack (DDoS), experts said. 

A DDoS is basically a bid to overrun the user capacity of a website, blocking it due to a high traffic. Hackers use software hidden in thousands of computer to direct such traffic to targeted websites. This technique turns unaware users' computers into "zombie" machines to carry out the attack. 

Former inspections by the Telecommunications Directorate (T?B) had revealed that Anonymous had uploaded such software in computers in Turkey, citing the number of such infected computers at 50,000. Local computers can sustain an attack even in cases that access from abroad is cut. Turkey hosts the fourth highest numbers of such...