Yes, people can still cheat with a camera and manipulating inputs. There will never be a way around that.
But that's entirely unchanged by adding malware, that, even if it could theoretically work, should be a literal crime with serious jail time attached. Client side validation is never security and cannot resemble security.
There are lots of options such that you can tune your false positive/negative rate. 🤷♂️ Tons of ways you can structure this depending on your game's tech.
No options that resemble legitimate or evidence based in any way.
If a computer has the exact same input and output tools as a human, you cannot possibly do better than guessing. It is a literal certainty that you will ban legitimate players doing nothing wrong for being too good if you try, and it's unconditionally not acceptable to do so.
I'm not sure why you think I'm saying client side is better when I called it malware.
There is no approach that is theoretically capable of doing anything at all to impact a camera and automated inputs, and there is no way of trying to do so that is acceptable. It's simply a reality of online gaming.