There are many online stories and blog posts teaching people how to make “passive income” by sharing spare computing power and/or unused internet bandwidth. When users willingly or unwillingly install such software on their computers, the systems become agents of a distributed network. The operators of this distributed network might monetize it by selling proxy services to their paying customers.
Even though the websites hosting the “passive income” software emphasize legitimate use cases, Trend Micro researchers have found that such software can pose security risks to the downloaders. This is because some paying customers of these proxy services may be using them for unethical or even illegal purposes.
Source: Trend Micro