From a link in the last sentence of the Bleeping Computer Article posted above by @itman (in case you didn't read that far) "...How was the Affirmativo - Keep Safe! Extension installed in Chrome? Affirmativo - Keep Safe! is currently being promoted through websites that state that you need to install the extension before you can leave the site. In many cases these advertisements are being displayed by adware that is installed on the computer. Unfortunately, many people do not realize they can simply close the browser in order to get away from these types advertisements..." https://www.bleepingcomputer.com/virus-removal/remove-affirmativo-keep-safe-chrome-extension
