First of all, this is extremely commonplace. You can go on Pastebin and find dumps like these easily at any given time.<p>Secondly, the way these leaks work is that attackers take a large list of leaked credentials from a generic dump from a hacked database. They then try each set of credentials against popular services like Netflix and Spotify. Usually, lots of attackers get the same accounts because they all use similar dumps and therefore get similar results. A lot of these lists of valid credentials end up on sites like Pastebin, and many are sold online as well. You can get cheap Netflix accounts for $1 or less easily on many hacker forums. Often, these accounts come with a warranty because many people who have obtained similar lists of accounts will change the credentials so they can keep individual accounts for themselves.<p>In conclusion, use unique passwords for every site, otherwise this could easily happen to you.