An anonymous reader writes: A company is going around buying abandoned Chrome extensions from their original developers and converting these add-ons into adware. The latest case is the Particle for YouTube Chrome extension, a simple tool that allows users to change the UI and behavior of some of YouTube's standard features. Because Google was planning major changes to YouTube's UI, the extension's original author decided to retire it and create a new one. This is when the a mysterious company approached the original author and offered to buy the extension from him for a price of his choosing. The original dev says he gave them a high price, but the company agreed to pay right away, but only after the dev signed an non-disclosure agreement preventing him from talking about the company or the transaction. Soon after the sale, the company issued an update that included code for injecting rogue ads on websites such as Google, Yahoo, Bing, Amazon, eBay, and Booking.com. Users also found other Chrome extensions that were also bought by the same company and had also been turned into adware, such as "Typewriter Sounds" and "Twitch Mini Player." According to some other Chrome extension devs, there are many companies willing to pay large sums of money for taking over legitimate Chrome extensions.