Romanian Hacker 'Guccifer' Pleads Guilty in Federal Court He previously claimed to have hacked into Clinton's private email server.

 -- The notorious Romanian hacker known as Guccifer has pleaded guilty in federal court to two hacking-related charges, according to prosecutors.

Guccifer, whose name is Marcel Lehel Lazar, 44, allegedly hacked into emails and social media accounts and released the personal information of numerous high-profile victims.

His alleged victims include former Secretary of State Colin Powell and family members of former President George W. Bush.

In a federal courtroom in Alexandria, Virginia, today, prosecutors said Guccifer hacked into the computers and social media accounts of about 100 Americans.

He ultimately pleaded guilty today to one count of unauthorized access to a protected computer and one count of aggravated identity theft. He could face up to seven years in prison, and he will be sentenced in September.

Earlier this month, Lazar made headlines when he said he had hacked into Hillary Clinton’s private email server, but officials remain skeptical of his claims.

In 2014, he was indicted on charges of wire fraud, unauthorized access to a protected computer, aggravated identity theft, cyberstalking and obstruction of justice, according to a press release from the U.S. Attorney’s Office for the Eastern District of Virginia.

Lazar hacked accounts of a "family member of two former U.S. presidents, a former U.S. Cabinet member, a former member of the U.S. Joint Chiefs of Staff and a former presidential adviser," the press release states.

"After gaining unauthorized access to their email and social media accounts, Lazar publicly released his victims’ private email correspondence, medical and financial information, and personal photographs," according to the press release.

Lazar initially pleaded not guilty to the charges against him on April 14, but a change-of-plea hearing was scheduled last week, according to court records.

In March, his extradition from Romania was approved, and he made his initial court appearance on U.S. soil on April 1. “Mr. Lazar violated the privacy of his victims and thought he could hide behind the anonymity of the Internet,” Dana J. Boente, U.S. attorney for the Eastern District of Virginia, said in a statement at the time of his extradition.

His court-appointed attorney, Shannon Quill, declined to comment on his case, citing office policy.

-Mike Levine contributed to this story.