SAN FRANCISCO — A Russian national accused of hacking into computers belonging to LinkedIn, Dropbox and Formspring has pleaded not guilty to all charges in a nine-count federal criminal indictment handed down in 2016.

Yevgeniy Aleksandrovich Nikulin, 30, of Moscow, made his first appearance in an American courtroom Friday after being extradited from the Czech Republic. Nikulin was arrested there Oct. 5, 2016, under an Interpol Red Notice, and he’s remained in Czech custody since.