How to completely format Mac to remove any malware ? Is there any guide somewhere? Is there any software to format MAC?
If your intention is to remove malware, there are so many other ways to remove malware from your mac device. You need not format the device, rather you need to get an antivirus software which would scan the device and remove the malware if found..
Follow the procedures to scan device for error
To remove malware from your mac you need not format your mac, what you can do it to install an antivirus protection which eventually works to remove malware out of your device.
The best way to remove infections off your device is by reinstalling your MacOS and your apps from scratch after wiping the hard disk.