Why has my Samsung Galaxy S2 become a data hog? My father has a Samsung Galaxy S2 with the stock GB and un-rooted. The phone has been working flawlessly, but lately (since about 2-3 days) it began to use a crazy amount of data.

He normally uses about 300 MB per month, but now the phone is using about 20-30 MB per hour during phone standby!.

Also he notices is that the battery is lasting about half of the previous time, which is evident in case of a long running process.

He didn't install/update anything lately and all the settings are set for minimal data use. (Like no Sync..etc). He also has all the known data-hog apps kept disabled. 

He has installed an app call “my data manager” and the app says that all the data is being used by OS services but there is no detailed information.

Just for clarification, he doesn’t have too much applications installed. Just: Whatsapp,  Viber, Facebook and Twitter. But as I said before, he has all the auto sync off, and all these apps where installed months ago.

My question is: Is there a program that can help us to find out what is going on? Something like a “on the fly” (real-time) data analysis?

Any other ideas on what could be happening here?

Thanks!
Edgar
After reading the comments, there's not much else to suggest for you to check on your phone.
So, here's two free APPs to help you out:
My Data Manager
Main features:
  • Simple to setup and simple to use.
  • Know what apps are using data with automatic monitoring of your app data usage.
  • Set usage alarms to avoid overage charges and “bill shock”.
  • Track historical app time and app usage using easy to understand visualizations.
  • Ensure you are using your ideal data plan and maximize how you use your data.
  • Save money by using your plans more effectively.


3G Watchdog
Main features:
  • monitors your Mobile Internet (4G/3G/Edge/GPRS) data usage.
  • shows a status icon (green/orange/red) in the notification bar.
  • has a detailed report page.