As you already know that the android is no longer safe because of uncontrolled app downloads. Here are few suggestions from redmondpie to protect your toys from trozans and viruses.
- Don’t Download Apps/APKs from untrusted sources: File-sharing websites like 4Shared and RapidShare are not recommended places for downloading APKs for apps. The person who uploads the APK can actually modify it beforehand to extract information from your device after your install it. Stick to trusted sources like Android Market, Amazon Appstore, GetJar and blogs like Redmond Pie, Addictive Tips, Android Police etc.
- Read Required Permissions Carefully Before Installing Apps: Apps on iOS do not get privileged access to system resources outside of the ones carefully assigned by Apple. Apps on Android, on the other hand, have deeper access to your device and you must be aware of what permissions they require. These can be read after tapping Download and before tapping Accept & Download in Android Market. If you’re downloading a live wallpaper app and it requires permissions for location via GPS, then you should stay away from it.
Source : RedmondPie.