Court documents filed at the US District Court in Northern California showed that Nikulin pleaded "not guilty" when he appeared before Magistrate Judge Jacqueline Scott Corley for an arraignment hearing on Friday morning.
"Nikulin pleaded not guilty to the charges. Magistrate Judge Corley scheduled Nikulin’s next appearance for status on April 2, 2018, and scheduled a detention hearing for April 4, 2018," the US Department of Justice said in a press release.
He was extradited to the United States from the Czech Repblic on Thursday night, his lawyer told Sputnik.
The prosecution is the result of a four-year investigation by the Federal Bureau of Investigation with the assistance of authorities in the Czech Republic and the US Department of Justice, the release said.
US Attorney General Jeff Sessions was quoted in the release as saying that the case is an example of "deeply troubling behavior once again emanating from Russia."
Nikulin faces charges of conspiracy, aggravated identity theft, trafficking in authorized access devices, computer intrusion and causing damage to a protected computer. Each of these charges carries sentences of 2 to 10 years of imprisonment, up to $250,000 fine and three years of supervised release.
Nikulin was detained in the Czech Republic on October 5, 2016, based on a warrant related to a criminal complaint by a US court. US authorities accuse the Russian national of allegedly hacking computers belonging to LinkedIn, Dropbox and Formspring online services and demanded his extradition.