New applications I haven't downloaded
I have a MacBook Pro 13-inch Mid 2012 with OS X Yosemite 10.10.3. Tonight I was looking for an application in the Launchpad when I noticed 4 new applications I haven't downloaded. They are Gmail, Youtube, Google Search and Google Drive. The last one I have downloaded a few years ago, but now is duplicated. I've tried to open them and nothing happens. The weirdest thing is that when I open the Applications folder in the Finder these applications aren't there. I don't know what source of witchcraft is this or if I have been hacked or something else. If anyone can help me, I would be so glad.
MacBook Pro, OS X Yosemite (10.10.3)