From being a simple chat app to one of the most popular messaging apps, WhatsApp has now come a very long way. The company keeps on infusing new features and makes sure its user's privacy is maintained and fully encrypted. Privacy has been one of the core features of the WhatsApp, however, despite its secure end-to-end encryption and two-step verification process, it is possible for hackers to sneak their way into your account and extract your personal data by various means. Though the app can be hacked to some extent only but can cost you huge.
Hackers can obtain your WhatsApp data by various means such as WhatsApp web or registering your number on another device. Even though the same WhatsApp number cannot be registered on two different smartphones simultaneously, the hacker can spy on your personal chats easily. Furthermore, hackers can gain access to your data by scanning WhatsApp Web QR code and access your WhatsApp conversation from anywhere in the world. Although, for this, the hacker needs to access your phone physically to access the QR code.
You can check if your WhatsApp account has been hacked or is active on an unknown device by clicking on the three dots (on the top right corner of WhatsApp window), go to WhatsApp Web and check the list of all open sessions. This will let you see all the devices that are connected to your WhatsApp account. If you witness this type of message, "This phone could not be verified," it means that your WhatsApp has been accessed by an unknown device. Furthermore, hackers can also sniff in your WhatsApp conversations with the help of some third-party software.
To protect your WhatsApp account from getting hacked, one should always log out of all active WhatsApp Web session you witness in the list. This will prevent hackers from accessing your account. Also, never connect your phone to an unknown WiFi connection as hackers can use the unique MAC address to obtain all your data. If your account has been already been hacked, immediately deactivate your account by e-mailing the issue to email@example.com. Do note that if you forget to reactivate it in 30 days, it will automatically get deleted. To add an extra layer of security over the app, enable 2-step verification under WhatsApp Account settings.