Disruptive macOS Malware Takes Over Mail App

Modern malware adopts a huge number of different forms, from the destructive to the secretive. Some will seek to damage your system, while others snoop around for personal information to steal. Because these are the types of malware infections that users most often encounter, it’s easy to think that an anti-malware solution is all you need to stay protected. However, some malware can exploit flaws at a more fundamental level in the system. Such is the case with the emergence of a recent malware threat for Mac users which abuses vulnerabilities in the native Mail app and Safari.

When a user opens a link within an email from a malicious source, or visits a particular website claiming to offer Safari tech support, the malware deploys to the Mac. By exploiting a vulnerability in Safari, the malicious software can take over the Mail app. At this point, it begins opening hundreds and hundreds of email drafts. These drafts appear faster than a user can close them. Eventually, they consume all available system memory and cause the machine to freeze entirely. A variant also attempts to open iTunes, though it does not achieve a “denial of service” level of severity in this instance.

The good news is that diligent users shouldn’t need to worry about this threat. A patch included with Apple’s release of macOS Sierra 10.12.2 means the malware can no longer affect your machine. However, this does highlight the reason to stay on top of Apple’s releases. Though this malware is more of a nuisance than a genuine threat to your data, it’s difficult to anticipate when unexploited flaws in the OS will become problematic. By keeping your system up to date and engaging with your security needs, you can continue to keep your machine secure.