The group posted nearly 9,000 documents it said were leaked from the CIA, in what it described as the largest-ever publication of secret intelligence materials.
WikiLeaks claimed that a vast trove of CIA documents, hacking tools and code representing “the majority of its hacking arsenal” were leaked within the cybersecurity community - and that it had received, and released, a part of them.
“This extraordinary collection, which amounts to more than several hundred million lines of code, gives its possessor the entire hacking capacity of the CIA,” it said, warning of a risk of cyberweapons proliferation.
Neither the CIA nor the White House would say if the documents were genuine.
If corroborated, the leak could represent a huge new embarrassment to US intelligence, adding to Edward Snowden’s 2013 expose of National Security Agency spying on Americans’ communications, and the arrest last year of an NSA official for removing massive amounts of top-secret material to his home over 20 years.
WikiLeaks said the data shows that the CIA is now rivaling the NSA in cyberwarfare, but with less oversight.
The archive shows the CIA exploiting weaknesses it discovers in hardware and software systems, including those made by US companies - without letting anyone know about the flaws in question.
Documents show the CIA has produced more than 1,000 malware systems - viruses, trojans and other software that can infiltrate and take control of personal electronics, WikiLeaks noted.
These hacking tools have targeted iPhones, Android systems such as the personal phone reportedly still used by President Donald Trump, popular Microsoft software, and Samsung smart TVs, which can be transformed into covert microphones, according to WikiLeaks.
The agency has also examined hacking into the electronic control systems on cars and trucks, potentially enabling it to control them remotely.
WikiLeaks said the CIA can get around the encryption technologies of popular apps like WhatsApp, Signal, Telegram, Weibo, and Confide by collecting communications before they are encrypted.