The extension with over 105,000 users does not ask for user permission before hijacking their CPUs to mine Monero all the time the Chrome browser is open.
Since early December, Archive Poster users have been complaining and giving the Chrome extension bad reviews, and on Friday, the Archive Poster developer Essence Labs confirmed the mining was taking place, but blamed it on a hack.
"An old team member who was responsible for updating the extension had his Google account compromised," Essence Labs said.. "Somehow the extension was hijacked to another Google account."
Archive Poster, which is advertised as a mod for Tumblr that allows users an easier way to "reblog, queue, draft, and like posts right from another blog's archive," has been shipping the hidden Coinhive cryptojacker for at least four versions —from 18.104.22.1684 to 22.214.171.1248.
As of Friday, the price of a single Monero reached $380, up from a mere $14 a year ago.