Yes, hackers can divert your calls and message. However, it is challenging to spot whether it is being done as the phone doesn’t ring in case of unconditional call forwarding. However, you can use a certain code to check if your calls are being forwarded.
You can also check with your service provider and let them know in case you feel suspicious and protect your data. Make a note of all the important codes, such as IMEI: *#06#, *#61# show if anyone receives your calls in case, they go unanswered.
To see the call forwarding status, check using *#62#. For the call forwarding number, use *#67#. To check all call forwarding information, use *#004#.