Have you ever heard of TR/ATRAPS.Gen2?
TR/ATRAPS.Gen2 is actually not a newborn Trojan horse. It can be detected by Antivir. With its powerful ability, it attacked many computers and it's been circulated for several years. These years, it has been changed a lot except its mission. It adds the infected machine to the ZeroAccess botnet and then downloads additional malware to monetize new asset. So it's very dangerous for your machine to meet TR/ATRAPS.Gen2. Once found, you should remove it immediately.