Just pay the tax and legalize your earning. If you can earn so much, few K is not an issue.

No way, if the asset is under your name. Unless you put others name but then, the asset is not own by you under the law.

Many Malaysian doesn't really know how IncomeTax dept works. Most ppl thought that they will investigate you. In fact, they don't. Where got so many investigators or inspectors around? Their job is very simple. If they found that you buy an asset and your income cannot be justified, they simply ask you to proof why you are not guilty (They practise China's law: You are assume guilty once they open a file for you). So you need to provide all the evidences to proof yourself not guilty (bank a/c, will, invoice, statement etc). Else fine min 3X to max 20X of the tax money plus 3 years jail.

Good luck