Speaking at an online press conference from the Ecuadorian Embassy in London, he said his group will work with technology companies to help defend them against CIA hacking tools, details of which he disclosed earlier this week.
Companies had asked for more details about the CIA cyber-espionage toolkit, said Mr Assange, adding: “We have decided to work with them, to give them some exclusive access to some of the technical details we have.”
He said some of the firms have already put counter measures in place, but others want more information.
“WikiLeaks has a lot more information on what has been going on with the cyber weapons programme,” he said.
He added that WikiLeaks wants to disarm the CIA’s “key attack code” before publishing more material.
Samsung has said it is “urgently” investigating claims from WikiLeaks that intelligence agencies have used the firm’s smart TVs as part of tools to spy on users.
The whistle-blowing website published thousands of documents it claims reveal the various hacking tools used by the CIA in the US, including techniques which target various consumer software including Windows, Google’s Android and Apple’s iOS.
WikiLeaks said software was developed to turn Samsung smart TVs into listening devices, a project codenamed Weeping Angel which the report claims also included input from the UK’s MI5.
It is understood former UKIP leader Nigel Farage spent over half-an-hour inside the embassy just before the press conference started.
Mr Assange has been living inside the embassy for more than four years after being granted political asylum by the Ecuador government.
He is wanted for questioning in Sweden over a sex allegation, which he denies, but faces extradition to the United States if he leaves the embassy.
Mr Assange said 78,000 pieces of information had been redacted from the documents published on Tuesday, which were code-named Vault 7.
The first part comprised 8,761 documents, called Year Zero, said to have come from an isolated, high-security network situated inside the CIA’s Centre for Cyber Intelligence in Langley, Virginia.
Asked if the CIA is causing damage to companies through the practices revealed by WikiLeaks, Mr Assange replied: “Yes - potentially billions of pounds of damage.”
He added the CIA has created a number of viruses which could “sit” on a computer, waiting for someone to burn a CD.
The documents seen by WikiLeaks had no references to terrorists or extremists, he said.