Usually it is for financial services companies that are mandated by Bank Negara to do so.

They will look out for bankruptcy, defaults, money laundering, bounce checks and financial related issues.
This is aside from criminal cases, civil cases, family background (not just criminal but politically connected, royalty connected, etc..).

Depending on the bank, most of them would use CCRIS check, some uses CTOS and some uses other providers.

Normally a bank would run the background check after you passed the interview because it costs the bank money to run these background checks. But do not worry, having high commitments doesn't affect the interview process nor your chances in being hired by the financial institution.