In under 24 hours, Apple updates malware definitions to detect Yontoo adware for Chrome, Firefox, and Safari

On Wednesday night we broke the news that a new trojan for OS X had been discovered, which downloaded and installed adware that injected ads into pages browsed by Chrome, Firefox, and Safari. As it has before, Apple has moved quickly to add definitions for the malware to its “Xprotect.plist” blacklist, as first spotted by MacRumors. Less than 24 hours is a very quick turnaround and Apple should be applauded for taking initiative to mitigate the issue. The definitions are part of the company’s basic anti-malware tools launched with OS X Snow Leopard in August 2009. It’s worth noting that the Russian security firm Doctor Web which found the threat first posted about it on Monday night. Apple did not become aware of the threat until the story got picked up by multipl