The 2017 leak of the CIA's cyberwar tools was the most damaging leak ever for the US syp group

A former employee in the CIA's cyber-spying operation was indicted Monday on charges of leaking hacking tools to WikiLeaks in one of the most damaging of the agency's breaches in recent years.

Joshua Schulte, 29, was charged with leaking unspecified information on the Central Intelligence Agency's intelligence-gathering capabilities to a group identified only as "Organization-1", which then released the information on the internet.

While the indictment gave no other details, in earlier filings Schulte's lawyer indicated the investigation involved the leak to WikiLeaks of the "Vault 7" collection of hacking tools, malware, viruses, trojans, and "zero day" exploits which comprised the CIA's most valuable tools for tapping into adversaries' computers.

WikiLeaks began releasing the 8,761 documents from Vault 7 in March 2017, embarrassing the agency and providing professional and amateur hackers around the world with the same tools that US spies used.

"The source wishes to initiate a public debate about the security, creation, use, proliferation and democratic control of cyberweapons," WikiLeaks said at the time.

It was arguably the worst of a series of leaks of some of the most closely held secrets of the US intelligence community, alarming the government's top security officials.

US officials have since said that the Vault 7 release, combined with the release of private communications of Democratic presidential candidate Hillary Clinton during the 2016 election, showed WikiLeaks to be a stateless hostile foreign intelligence service.

Schulte was an early suspect but was only quietly charged in September 2017 with having a large cache of child pornography on his computer.

In a superseding grand jury indictment Monday, he was hit with 13 charges related to the theft and leaking of classified defense information and child pornography.

"As alleged, Schulte utterly betrayed this nation and downright violated his victims. As an employee of the CIA, Schulte took an oath to protect this country, but he blatantly endangered it by the transmission of classified Information," said FBI Assistant Director-in-Charge William Sweeney Jr.

"To further endanger those around him, Schulte allegedly received, possessed, and transmitted thousands of child pornographic photos and videos."

Joshua Schulte was charged with leaking unspecified information on the CIA's intelligence-gathering capabilities to a group identified only as "Organization-1"