I have came across this type of device of backdooring/infecting while browsing some websites. well ya, these sites tend to cater to "hackers" or misled users. they tell you to download the file if you want their product, but you have to unlock the rar with their key. of course, i didnt fall for their trickery. so virus boxes' target audience: "people who dont know better."

i think ur all safe here.