If you search on Internet, you would be able to find apps that are modified to insert code that shows ads here and there. For example, you can take the official WhatsApp Android APK and insert code to show a banner ad on some or all pages.
The modified app holds a different signature so it is not a replacement for the original app but would be a different app technically.
So, the person modifying the app would be able to make money off WhatsApp which goes against the very philosophy of WhatsApp's user experience for having an ad free experience.
I would like to know if this qualifies as a cyber-crime and if yes, what are the implications of having done so? Are there any possible legal implications?
The context is in Indian jurisdiction.