content: It's a Trojan. Different from a virus because a Trojan gets installed as part of another installer as here and it requires the user to do the install. Viruses can install without any user interaction and there aren't any for the Mac. There have been a few attempts but they don't propagate so Trojans are a better way to get malware onto a Mac (or Linux and Windows for that matter). Macs by default wouldn't allow this package to install but some users turn off gatekeeper to allow them to install unsigned packages. Meanwhile, Apple is updating signatures for the systems to remove this. The nice thing about Macs is there's so few malicious packages that Apple is able to create specific signatures for each and distribute them so you don't get the false positive that heuristics used on windows AV packages can cause. As long as Apple stays ahead of the game and the majority of macs retain default security settings malware won't be able to get a hold on the Mac ecosystem.