NEW YORK — A prominent hacker set to be sentenced in federal court this week for breaking into numerous computer systems worldwide has provided a trove of information to the authorities, allowing them to disrupt at least 300 cyberattacks, according to a newly filed government court document.
The targets of the planned attacks included the US military, Congress, the federal courts, NASA, and private companies, the document stated.
The hacker, Hector Xavier Monsegur, also helped the authorities dismantle an aggressive cell of the hacking collective Anonymous, leading to the arrest of eight of its members in Europe and the United States, including Jeremy Hammond, whom the FBI said was its top “cybercriminal target,” the document says. Hammond is serving a 10-year prison term.
The court document was prepared by prosecutors who are asking a judge, Loretta A. Preska, for leniency for Monsegur because of his “extraordinary cooperation.” He is set to be sentenced Tuesday in US District Court on hacking conspiracy and other charges that could result in a long prison sentence.
It has been known since 2012 that Monsegur was acting as a government mole in the shadowy world of computer hacking, but the memorandum submitted to Preska late Friday reveals for the first time the extent of his assistance and what the government perceives of its value. It also offers the government’s first explanation of Monsegur’s involvement in a series of coordinated attacks on foreign websites in early 2012.
The whereabouts of Monsegur have been shrouded in mystery. Since his cooperation with the authorities became known, he has been vilified online by supporters of Anonymous. The memo says that, meanwhile, the government became so concerned about his safety that it relocated him and his family.
“Monsegur repeatedly was approached on the street and threatened or menaced about his cooperation once it became publicly known,” says the memo, which was prepared by the office of Preet Bharara, the US attorney in Manhattan.
Monsegur’s role emerged in March 2012 when the authorities announced charges against Hammond and others. A few months later, Monsegur’s bail was revoked after he made “unauthorized online postings,” the document says. He was jailed for seven months, then was released on bail in December 2012, and has made no further postings, the memo says.