PARIS – Up-to-date Microsoft customers are safe from the purported National Security Agency spying tools dumped online, the software company said Saturday, tamping down fears that the digital arsenal was poised to wreak havoc across the internet .

In a blog post , Microsoft Corp. security manager Phillip Misner said that the software giant had already built defences against nine of the 12 tools disclosed by TheShadowBrokers, a mysterious group that has repeatedly published NSA code . The three others affected old, unsupported products.

"Most of the exploits are already patched," Misner said.

The post tamped down fears expressed by some researchers that the digital espionage toolkit made public by TheShadowBrokers took advantage of undisclosed vulnerabilities in Microsoft's code. That would have been a potentially damaging development because such tools could swiftly be repurposed to strike across the company's massive customer base.

Those fears appear to have been prompted by experts using even slightly out-of-date versions of Windows in their labs. One of Microsoft's fixes, also called a patch, was only released last month .

"I missed the patch," said British security architect Kevin Beaumont, jokingly adding, "I'm thinking about going to live in the woods now."

Beaumont wasn't alone. Matthew Hickey, of cybersecurity firm Hacker House, also ran the code against earlier versions of Windows on Friday. But he noted that many organizations put patches off, meaning "many servers will still be affected by these flaws."

Everyone involved recommended keeping up with software updates.

"We encourage customers to ensure their computers are up-to-date," Misner said.