A cyber-attack that has hit 150 countries since Friday should be treated by governments around the world as a "wake-up call", Microsoft says.
The
software vulnerabilities hoarded by governments had caused "widespread damage".
The latest virus exploits a flaw in a version of Microsoft Windows first identified by US intelligence.
There are fears of further "ransomware" attacks as people return to work on Monday.
Many firms have had experts working over the weekend to prevent new infections. The virus took control of users' files and demanded $300 (£230) payments to restore access.
The spread of the virus slowed over the weekend but the respite might only be brief, experts have warned. More than 200,000 computers have been affected so far.
A statement from Microsoft president and chief legal officer Brad Smith on Sunday criticised the way governments store up information about security flaws in computer systems.
"We have seen vulnerabilities stored by the CIA show up on WikiLeaks, and now this vulnerability stolen from the NSA has affected customers around the world," he wrote.
"An equivalent scenario with conventional weapons would be the US military having some of its Tomahawk missiles stolen."
