London (CNN)A British hacker whose cyberattacks took the nation of Liberia offline has been jailed for almost three years.
Daniel Kaye launched a series of attacks on Liberian cell phone operator Lonestar in October 2015, which became so powerful they knocked out the west African country's internet the following year.
Kaye, 30, had been hired to carry out the attacks by a senior employee at rival operator Cellcom, Britain's National Crime Agency said in a statement, although there is no suggestion that Cellcom was aware of the activity.
He pleaded guilty to creating and using a botnet, a series of computers connected in order to attack systems, and possessing criminal property last month. Kaye was sentenced on Friday at Blackfriars Crown Court in central London to two years and eight months in prison.
While living in Cyprus, Kaye used a botnet he had created to trigger repeated distributed denial of service (DDoS) requests on Lonestar, causing the company to spend around $600,000 in remedial action.
The additional impact of customers leaving the network caused the company to lose tens of millions of dollars in lost revenue, the NCA added.
Following his arrest in February 2017, Kaye was extradited to Germany, where he also admitted to attacks on Deutsche Telekom that affected around 1 million customers in November 2016.
"Daniel Kaye was operating as a highly skilled and capable hacker-for-hire," Mike Hulett, Head of Operations at the NCA's National Cyber Crime Unit, said.
"His activities inflicted substantial damage on numerous businesses in countries around the world, demonstrating the borderless nature of cyber crime," he added. "The victims in this instance suffered losses of tens of millions of dollars and had to spend a large amount on mitigating action."