Grand National extortion attacks 'unlikely'

The massive bandwidth extortion attacks that crippled online gambling sites last year are unlikely to be repeated ahead of this year's Grand National horse race, which takes place on Saturday, industry experts predicted on Friday.

According to police sources, complaints of attacks have eased off since the arrest of a gang believed to be behind a protection racket which forced Web-gambling firms to pay up or face long periods of downtime on their systems.

"An attack is unlikely," said a spokeswoman for the National Hi-Tech Crime Unit. "We arrested the people behind it in Russia last year."

Bandwidth attacks using networks of compromised computers, also known as distributed denial-of-service (DDoS) attacks, are used by hackers to cripple a Web site by sending its servers more data than they can process, ultimately forcing it offline. This type of attack was used last year against several betting Web sites to disrupt their operations.

"The number of [DDoS attacks] we get phone calls about is very low now," said Paul Lawrence, general manager at Top Layer, a vendor involved in protecting Web sites from DDoS attacks. "I can't say there's been an increase."

Last year, Russian police claimed that the gang behind the attacks has caused about £40m in damage. Yevgeny Yakimovich, the chief of the Russian Interior Ministry's Department K, which tackles cybercrime, said DDoS attacks were launched at nine UK bookmakers. Those responsible then demanded up to £28,000 before they would stop the attacks, which typically coincided with major sporting events.