You must be getting WhatsApp messages from unknown number for several reasons. First and foremost, it's possible that your number has ended up in a spammer's database, and they share your number with other spammers, which in return send you more spam messages.
Why do I get random WhatsApp messages? Spam messages are often sent by bots to randomly generated phone numbers, meaning anyone might receive a random WhatsApp message. If you receive a spam message, don't click any links in the message and block the sender's number.
However, just like regular SMS or phone calls, it's possible for other WhatsApp users who have your phone number to contact you. They may or may not be saved in your contacts.
Use Reverse Phone Number Lookup Some popular WhatsApp number trackers include Information, TrueCaller, US Search, Spy Dialer (only U.S.-based numbers), and TruthFinder.
Can people see my number on WhatsApp if they are not in my contacts list? Not directly. People only see your number on WhatsApp if they already have it saved in their contacts list.
All WhatsApp accounts are tied to mobile phone numbers. Since it's common for phone numbers to be recycled by mobile providers, it's possible that the previous owner of your current phone number used WhatsApp.
Tracing a WhatsApp Number Make sure the phone number's area code matches where they live. Call the number from your phone to see who answers. Report phishing, fraud, spam, and suspicious activity to WhatsApp.
Truecaller is now able to identify unknown callers from WhatsApp on your phone. The easiest way to enable this feature is to: On your device, open the Truecaller app. Click on Settings>Calls>Enable option>Identify calls on other apps Truecaller.
While it's technically possible for vulnerabilities to exist in messaging apps like WhatsApp, simply replying to a message typically does not allow someone to hack your phone. WhatsApp uses end-to-end encryption, which means that your messages are secure during transmission.