Qareaste.info is a malicious browser extension, constantly redirecting the user to http://www.qareaste.info/. Qareaste.info is the result of the penetration of adware, which leads to other malicious programs.
Nav-goo.com is a malicious search webpage looking and functioning like a familiar search engine with useful functions. This hijacker comes bundled with freeware via its installers, web-clients and other special software, without user consent. It changes browser default homepage, search engine and other settings.
Search.instasrch.com is another browser hijacker, changing browser settings, including the default search engine and replacing the homepage on http://search.instasrch.com/search. These changes can not be undone later.
StalinLocker Ransomware is one of the extorting cryptographers, activated in early May this year. It looks like an uncleaned cryptographer, because usually similar viruses encrypt key files on your PC, changing their structure and renaming the names to a set of symbols and letters. This encryptor acts differently.
If you notice that your browser homepage is changed to https://bronav.com, then this probably means that your PC is infected with Bronav.com browser hijacker. Bronav.com comes in the form of a browser extension and changes the settings of your browsers.