Google is hosting dozens of extensions in its Chrome Web Store that perform suspicious actions on the more than 4 million devices that have installed them and that their developers have taken pains to carefully conceal. The extensions, which so far number at least 35, use the same code …

The people overseeing the security of Google’s Chrome browser explicitly forbid third-party extension developers from trying to manipulate how the browser extensions they submit are presented in the Chrome Web Store. The policy specifically calls out search-manipulating techniques such as listing multiple extensions that provide the same experience …