I have a Samsung galaxy nexus with official Android 4.1 running. I sometimes get strange notifications with a green + as the icon, saying you have won..., click here to..., or similar messages. Of course I would not open any of them as they immediately appear suspicious. I also sometimes get some shortcut icons on the home screen looking like games, etc. I do not find them in the app list though. I have had similar incidents before upgrading to 4.1.

Does anybody get things like these? Is this a malware living in my phone? Any thoughts would be highly appreciated.