MacKeeper antivirus software for Mac OS X has been found to be vulnerable to a critical remote code execution vulnerability. The vulnerability allows an attacker to execute arbitrary code with root privilege on the compromised system with “little to no user interaction” The software is infamous for its noisy “clean up your Mac” pop-under ads that stress the need for a system cleanup. The software has been downloaded more than 20 million times, but the company is not aware of any security breach exploiting this vulnerability.
Source: https://thehackernews.com/2015/05/mackeeper-antivirus.html