The Pirate Bay was caught using code to borrow CPU power from website visitors. The idea of using browsers as a botnet has been kicking around since at least 2013. The resulting botnet could then be used for cracking passwords, mining cryptocurrencies or conducting distributed denial-of-service attacks. Brannon Dorsey wanted to find out how much power he could harness from computers on the web, as well as how cheaply and anonymously he could do it. Dorsey’s work shows hijacking browsers with malicious advertisements could mean more intensive DDoS attacks.”]
Source: https://www.cuinfosecurity.com/coming-battle-for-your-web-browser-a-10585