QuasarRAT can hide process windows and make web requests invisible to the compromised user. Requests marked as invisible have been sent with user-agent string `Mozilla/5.0 (Macintosh; Intel Mac OS X 10_9_3) AppleWebKit/537.75.14 (KHTML, like Gecko) Version/7.0.3 Safari/7046A194A` though QuasarRAT can only be run on Windows systems.