FBI investigating source of WikiLeaks' purported CIA document dump

— -- The FBI is investigating the source of documents published by WikiLeaks that purport to be from the CIA, a source familiar with the matter confirmed to ABC News.

WikiLeaks published more than 8,000 pages of documents that it says are classified files from the CIA that purportedly reveal secrets about agency hacking tools used to break into computers, cellphones and smart TVs.

In a statement released earlier Wednesday, the CIA said it had "no comment on the authenticity of the documents."

The CIA then said that its "mission is to aggressively collect foreign intelligence overseas to protect America from terrorists, hostile nation states and other adversaries" and that it is "legally prohibited from conducting electronic surveillance targeting individuals here at home."

The activities conducted by the CIA are subject to "rigorous oversight" to ensure that they comply fully with the law and U.S. Constitution, it said.

"The American public should be deeply troubled by any Wikileaks disclosure designed to damage the Intelligence Community’s ability to protect America against terrorists and other adversaries," the CIA said. "Such disclosures not only jeopardize US personnel and operations, but also equip our adversaries with tools and information to do us harm."

WikiLeaks said a former government contractor circulated the files, in a statement accompanying the documents.

"Recently, the CIA lost control of the majority of its hacking arsenal including malware, viruses, trojans, weaponized 'zero day' exploits, malware remote control systems and associated documentation. This extraordinary collection, which amounts to more than several hundred million lines of code, gives its possessor the entire hacking capacity of the CIA. The archive appears to have been circulated among former U.S. government hackers and contractors in an unauthorized manner, one of whom has provided WikiLeaks with portions of the archive," the whistleblower group said.

ABC News' Pierre Thomas contributed to this report.