The search giant told vnunet.com that the acquisition was completed earlier this month, but declined to provide specific terms of the deal.
A notice on GreenBorder's website says that the company has stopped selling its security software, and that customers will be supported until their existing contracts expire.
The software uses a virtualisation technique known as a 'sandbox', in which the browser runs entirely within a separate secured system.
This prevents any attacks or exploits from using flaws in the browser to access system resources and run malware.
Cotton seedling freezes to death as Chang'e-4 shuts down for the Moon's 14-day lunar night
Fortnite easily out-earns PUBG, Assassin's Creed Odyssey and Red Dead Redemption 2 in 2018
Meteor showers as a service will be visible for about 100 kilometres in all directions
Saturn's rings only formed in the past 100 million years, suggests analysis of Cassini space probe data
New findings contradict conventional belief that Saturn's rings were formed along with the planet about 4.5 billion years ago