iPhone 15 Camera Hacked?

I think you have two separate incidents that are unrelated and merely a coincidence.

I have a strong online presence, I run several large Facebook Groups, participate here and other public forums and social media platforms. I use my real name on the websites etc. I get scam texts, Facebook Messenger notes etc. and many start with lines such as, Saw you online, I saw you in this video, I saw you OMG and on and on. This is a common hook by scammers to get you to click on a link. Don’t ever do it. Just ether message and go on about your day.

The camera light is a separate issue. Please follow this path,

iPhone > Settings > Privacy & Security > Camera > those are all the apps you’ve given permission to use your camera

If you see apps that you don’t want using your camera, switch it off.

I suspect X was given permission (by you) to use your camera. If that makes you uncomfortable, switch it off.

I have several bank apps that have permission to use my camera. Why would a bank want permission to use my camera? It allows the app to scan credit and debit cards for card activation. So, there are lots of reasons an app might want access.

I think you’re fine, and had a coincidence and given your context, you did the right thing. Going forward, you know how to control apps having access to features on your iPhone.

If you feel an unauthorized person/app is remotely using, controlling or monitoring your device, then that is possible only if you have done one or more of the following Don'ts...

1. Don't hand over an iPhone to kids or to a stranger without Enabling Guided Access
2. Don't share Apple IDs
3. Don't Jailbreak
4. Don't share sensitive information pertaining to your device
5. Don't give in to Phishing
6. Don't plug in your device in Airports and Public places through third-party cables and trust the device. Beware of Juice Jacking. (Especially in India)
7. Don't leave your iPhone unlocked and unattended in public places like offices, schools, malls, etc.

If one of the above is true then quickly change the Apple ID Password and Return iPhone settings to their defaults.

Keep the iPhone updated to the latest iOS always and never Jailbreak. That's it.

iOS / iPadOS devices cannot be hacked or infected with Virus / Malware / Spyware *** unless you have intentionally downloaded spurious software or unauthorized apps directly from the internet and installed them on your device or/and have Jailbroken. 

It (Hacking) also depends on how careful you are in sharing sensitive and valuable information pertaining to your iPhone such as Passcode, Password, etc with your friends and family members.

Be judicious when sharing the device's sensitive and valuable information with friends and family members.

**The primary reason for this is Sandboxing. All third-party apps are “sandboxed”, so they are restricted from accessing files stored by other apps or from making changes to the device. Sandboxing is designed to prevent apps from gathering or modifying information stored by other apps.

Security of runtime process in iOS and iPadOS - Apple Support

The sandbox on an iPhone is a security feature that creates a restricted environment for each app to run in isolation from other apps and the operating system. It is a core component of iOS's security architecture and plays a crucial role in making iPhones more secure.

If you doubt the authenticity of the information provided earlier, you have two alternatives:

1. Report the hacking incident to local law enforcement authorities and actively pursue the case.
2. Accept the credibility of the information; it is impervious to hacking. Just as some individuals hold unconventional beliefs, such as a flat Earth or moon landing denial, one has the freedom to believe in anything. The choice ultimately rests with you in this open and free world.

Just because you see the light in the Notch/Dynamic Island does not mean the camera is actually taking photos or videos. You can always check to find which app is accessing the camera by opening the Control Center (swipe down from upper right corner) and it will display at top of screen what’s active.

Tap the information (icons and text) and you’ll see below image next.