iPhone virus keeps switching my camera on

You don't have a virus. Updates for the iPhone can ONLY come directly from Apple.

Try and find an actual reason for the camera being enabled.

Such as, do you have third party apps installed from the App Store that upon initial use asked for permission to use the camera. Any such app may have hid the camera activity light, but the OS update/upgrade no longer allows the app to do that.

Chippyandbonny wrote:

I received notification to update my iPhone in my settings, I now have a virus which constantly switches the camera on whilst using the phone .?

It's either not a virus, maybe a hardware issue, or you have become interesting to an immensely well-funded adversary.

Starting with what is a more likely case among the possibilities here, which app is using the camera?

To determine that, open Control Center, and look:

Access Control Center on your iPhone - Apple Support

Which app is using the camera will be displayed at the top center, and you can tap for a few more details.

Nope. There are no viruses in the wild that can infect an iPhone that has not been jailbroken.

Look for another explanation.