When I was going to Worldometer’s coronavirus page, it would redirect me to some stupid scam web site saying “you made 5 billionth search”. It happened only one one of my devices, the one given to me by my employeer, and the one I least expected to be infected, since I use it strictly for work purposes.

It turns out nothing was wrong with the device: it’s a targeted ad on the site itself that did it. The solution was to change my Google Ads ID in the settings (Settings -> Privacy -> Ads -> Reset advertising Id on Android).