If you notice any messages you didn’t send or messages you’ve received from people you don’t know, or if you see any contacts that aren’t yours, this might be a sign that there is an interloper on your account.
Oftentimes, heavy apps running in the background of your phone cause the phone to warm up, this could be caused by spyware.
If your smartphone battery drains so quickly by just leaving it on mobile data or wifi, then there is a possibility of spy software running on your smartphone without your consent.
Another notorious way someone can gain access to your WhatsApp account is by obtaining the text verification code. If WhatsApp sends you a text verification code that you didn’t invoke, it’s best to ignore it.
Click on the link below to get full details on how to fix it after my Whatsapp has been attacked.