A U.S. hacker who hooked up a botnet within Newell Rubbermaid's corporate network was sentenced to 41 months in prison on Wednesday, according to the U.S. Department of Justice.

Robert Matthew Bentley, of Panama City, Florida, must also pay US$65,000 restitution. He was sentenced in U.S. District Court for the Northern District of Florida.

Bentley could have received a 10-year sentence. He pleaded guilty to charges of computer fraud and conspiracy to commit computer fraud for using the botnet to install advertising software on PCs located throughout Europe without permission.

Newell Rubbermaid, which makes products such as Sharpie markers and plastic food-storage containers, reported their European computer network had been hacked around December 2006. At least one other European-based company also complained.

Bentley's indictment was enabled by investigations conducted by several law enforcement agencies worldwide, including London's Metropolitan Police Computer Crime Unit, the U.S. Secret Service, the U.S. Federal Bureau of Investigation, the Finland National Bureau of Investigation and other local U.S. agencies.

Others who helped Bentley are still under investigation, the department said. Bentley received a commission from a company called DollarRevenue for every installation of the advertising software.

Ad software can be very difficult to remove and trigger unwanted pop-ups. Many hackers have become astute at installing the software through surreptitious means, such as exploiting software vulernabilities in a PC's operating system or Web browser.

In December 2007, DollarRevenue was fined ¬1 million (US$1.54 million) in the Netherlands, one of the largest fines ever levied in Europe against a company over adware. That investigation found that hackers were paid ¬0.15 each for installation of DollarRevenue software on computers in Europe and $0.25 for PCs in the U.S.