Browser-test.info is a forced Firefox extension. Malwarebytes can detect and remove this unwanted program. The extensions that belong to this family are capable of downloading code after the installation to perform several functions:search hijackers, crypto-currency miners and hackers. The full version of Malwarebyte protects users from these extensions by blocking the sites that spread them and the domains they contact for additional code. Users were protected even before we added the domains to the blocklist:Users were protected.”]
Source: https://forums.malwarebytes.com/topic/238379-removal-instructions-for-browser-testinfo/