Karim Baratov, the Canadian-Kazakh hacker who helped Russia's FSB compromise millions of Yahoo email accounts, has been sentenced to five years in prison.
Baratoc was also fined $250,000 during sentencing at a court in San Francisco, California on Tuesday.
Baratov pleaded guilty to nine felony hacking charges, including aggravated identity theft and conspiring to commit computer fraud, in November. At the time, he admitted that he began hacking as a teenager and charged customers $100-a-go to access web-based emails.
Hackers such as Baratov ply their trade without regard for the criminal objectives of the people who hire and pay them
According to the Justice Department, the hacker worked under the guidance of two Russian Secret Service (FSB) agents, Igor Anatolyevich Sushchin and Dmitry Aleksandrovich Dokuchaev, who found Baratov's hacker-for-hire website and hired him to target a number of Yahoo accounts.
After Baratov's guilty plea, his lawyers told reporters he hacked only eight accounts and did not know that he was working for Russian agents connected to the Yahoo breach.
Prosecutors called Baratov, who was born in Kazakhstan but lived in Toronto, Canada, an "international hacker-for-hire" who hacked without asking questions.
"The sentence imposed reflects the seriousness of hacking for hire," acting US Attorney Alex Tse said in a statement.
"Hackers such as Baratov ply their trade without regard for the criminal objectives of the people who hire and pay them. These hackers are not minor players; they are a critical tool used by criminals to obtain and exploit personal information illegally.
"In sentencing Baratov to five years in prison, the Court sent a clear message to hackers that participating in cyber attacks sponsored by nation states will result in significant consequences."
Baratov, who has been in custody since his arrest, told the judge that his time behind bars has been "a very humbling and eye-opening experience".
The US Justice Department also charged two Russian spies with orchestrating the 2014 security breach at Yahoo to steal data from 500 million users. Anatolyevich and Dokuchaev remain at large, but prosecutors believe they are living in Russia under the protection of the authorities.
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