Archive Poster, a widely used extension which allowed Tumblr users to “reblog, queue, draft, and like posts right from another blog’s archive” was said to be hijacking the CPUs of over 1,05,000 users to secretly mine Monero cryptocurrency.
The extension kept mining the cryptocurrency until the browser was open and did not prompt any permission from the users. The process is popularly known as cryptojacking. Besides, there is no option for the user to shut the process but to uninstall the extension or close the website executing the process.
After the extension was taken down, another extension ‘[SAFE] Archive Poster’ has emerged. Offered by ‘Archive Poster’, the extension does not provide any screenshot of how it works, which raises serious concerns about the reliability of the extension.