First things first: uninstall them.
Nothing should be able to install apps remotely unless it has your Play Store login, so as a precaution I'd change your Gmail password.
There are a lot of things on the Web that will automatically download apps though (dodgy ad networks), but that shouldn't install them unless you click on something else (fake "antivirus" popups for example). So the next thing I'd check is whether you've installed some other shady app which is responsible for this. Stuff installed from places other than the Play Store should be more suspect, as should and dodgy app stores like mobogenie.