Two European men have been charged with hacking U.S. retail websites and causing more than $400,000 in damage through a series of distributed denial-of-service (DDoS) attacks in 2003.

Lee Graham Walker, 24 of Bleys Bolton, England and Axel Gembe, 25 of Germany were each charged with one count of conspiracy and one count of intentionally damaging a computer system. Both men face up to 15 years in prison if convicted, according to a statement from the FBI's field office in Los Angeles.

Both men live outside of the United States, and warrants have been issued for their arrests, Erik Silber, an assistant U.S. attorney, told SCMagazineUS.com Tuesday.

Walker and Gembe together developed a network of computers that Gembe used to launch the attacks. They used the botnet to send a large amount of packet requests to a number of retail websites.
 
“The purpose was to overwhelm the websites, so that they couldn't respond to the public,” Silber said.

The plan worked — the websites crashed because they could not handle the large number of requests coming in.

The websites targeted were Rapid Satellite in Miami and Weaknees in Los Angeles. Both companies reported the attacks caused a two-week halt in their business and more than $200,000 in losses.

Walker and Gembe weren't the only individuals involved in the conspiracy, however. They were allegedly hired by Saad Echouafni, former head of satellite communications company, Orbit Communications, and associate Paul Ashley, former head of Creative Internet Techniques.

Echouafni and Ashley were charged in 2004 for their role in the conspiracy — hiring Walker and Gembe to launch the DDoS attacks against retail Echoufani's retail competitors. 

“The case against Echouafni and Ashley was the first successful investigation of a large-scale DDoS attack that was waged for a commercial purpose in the United States,” an FBI statement says.

In 2005, Ashley pleaded guilty and served a two-year prison sentence. Echouafni, who goes by the alias of Jay R. Echouafni, is still wanted by the FBI. Authorities believe he may have fled to Morocco.