Daniel Kaye was hired in 2015 by Cellcom, a telecoms company, to launch a series of debilitating cyberattacks on rival firm Lonestar, a Liberian phone and internet provider.
The self-taught hacker was paid £30,000 by the company to disrupt Lonestar’s services between October 2016 and February 2017.
Britain’s National Crime Agency (NCA) said the attack overwhelmed the Liberian firm’s computer network and cost it tens of millions of dollars as it fought the distributed denial of service (DDoS) assaults on its computer network
In November 2016, the impact of the attack disabled internet connections across Liberia, in what is thought to be the first ever instance of a single hacker disabling an entire nation’s internet access,.
“Hundreds of thousands of internet-ready devices are in effect taken away from their usual use,” prosecutor Robin Sellers told Blackfriars Crown Court.
Kaye carried out his plan by adapting a powerful computer virus into a botnet, which turned thousands of devices connected to the internet into “zombies”, the court heard.
A botnet is a collection of computers that have had malicious software installed on them, thereby allowing someone to direct them as a group from afar.
Incredibly high traffic resulting from the botnet caused the internet outage in Liberia.
The 30-year-old launched the cyberattacks from Cyprus, where he was living at the time.
A European Arrest Warrant was issued for Kaye and when he returned to the UK in February 2017, he was arrested by NCA officers, following an investigation involving the NCA’s German counterpart, the Bundeskriminalamt (BKA).
Sentencing, Judge Alexander Hugh Milne QC said Kaye had pursued a “large scale unlawful” attack on Lonestar’s computer systems.
“You were paid by a rival company to disrupt and undermine the legitimate business of Lonestar,” he said.
He said Kaye’s actions were a “cynical and financially-driven attack upon a legitimate business enterprise”.
“Daniel Kaye was operating as a highly skilled and capable hacker-for-hire,” Mike Hulett of the NCA.
“His activities inflicted substantial damage on numerous businesses in countries around the world, demonstrating the borderless nature of cyber crime.”
Investigators in Britain, Germany and Cyprus were involved in the effort to jail Kaye, who wept during his sentencing hearing on Friday.
Agencies contributed to this report