How to check if my MacBook is being hacked?

Here is an excellent article written by a respected forum contributor regarding safe computing practices which will help minimize risks:

Effective defenses against malware and other threats - Apple Community

If you are a prominent figure or other high value target, then other more extreme measures should also be implemented as well, otherwise the average person has little to worry about if they are careful with the sites they visit and the links they click plus utilize good hard to guess passwords or better yet use Two Factor Authentication (2FA) or even better Multi-Factor Authentication (MFA) on your online accounts. I will avoid even reading any text messages from unknown sources because some of them have been known to corrupt an iPhone (sometimes just by receiving a carefully constructed message, but not much I can do about the latter).

Remember anyone with physical access to your devices (especially unsupervised) even if the device is locked can have the device compromised if the person's intent is to attack or monitor you. I know many people who travel who will leave their main phone & computer at home and only use special devices when travelling because of the security checks in various countries.

In short most average people just need to follow safe computing practices and keep an eye on your credit cards & bank accounts. If you are doing these things, then don't spend time worrying about it since there is only so much you can do.

Always have frequent and regular backups of your computer (or devices) and all external media (including the cloud) which contains important & unique data.

along with ku4hx's good advice, please see these apple support pages:

Checklist: If you want to see if anyone else has access to your device or accounts - Apple Support

If you think your Apple ID has been compromised - Apple Support

Check your router for unknown and unidentifiable IP addresses. Some may only appear to be rogue IPs that are legitimate and related to what you've allowed into your system.

The best defense is to be intimately familiar with the workings of your Mac and router and be suspicious of any of "odd" activity. Hackers have a plan and that can be just nosiness, but it also can involve bank accounts, credit cards and such. Be vigilant and be safe and stay away from know hacker sites, warez and such as that.

And be wary of free apps; many are just fine. But if it just seems too god to be true or is described and being cracked and the like it's likely bad news.

Mohelbaz11 wrote:

any ways to check if some one hack or use my information or steal my data through by network or unauthorised app ? In my mac book

thanks

[Re-Titled by Moderator]

Q - " if some one hack "

A - To Hack the computer would require the Hacker to have Direct and Physical Access to this computer

A - Has the user given someone access to this computer with the Admin Account Password ?

Q - " or unauthorised app "

A - Generally, an Application that is download requires the user ( you ) to Download and Grant Permission to install such an Application.

A - There is Adware & Malware which will affect the computer and is generally downloaded from “ Shady “ Websites or Developers who Inject this software into the download.

Should “ Certain & Specific Software “ referenced from above be installed - it will negatively impact macOS. It is suggested, to download directly from an ASC Contributor ( Not me ), the application Malwarebytes for Mac. 

It is free or paid for added features. 

Run the Application and it should remove the malware / adware. Once done, restart computer and test.

Otherwise, follow the solid advise from Both of the Previous Contributors

Based on my very limited education in computer forensics, it would be very difficult for you to tell on your own with what is built-in. You need to consult a forensic diagnostic company to determine if you have been hacked and what was exfiltrated.

The ability to hack a Mac remotely is almost impossible.

What “unauthorized” app did you install, or what did you do to provide someone either remote or physical access to your Mac?