Possibly added there for your protection against ...... Your best bet is to go to Avast and find your information there. https://help.avast.com/en/av_free/12/settings_sandbox_virt_proc.html Click the word Sandbox on this page. If need further help : https://forum.avast.com/index.php find Sandbox and browser in the list of help articles and browse for a solution or post your question. It would be best to know your program before making decisions. Please let us know if this solved your issue or if need further assistance.