I am a foreigner working in Malaysia and already have a wife in my home country. Can I marry again here?

You must be upfront about your existing marriage, and the polygyny procedure in the state where you marry must be followed. The religious affairs office usually asks for marital status documents from your home country or embassy. Claiming to be single or hiding a wife back home is deception that can lead to legal action and bring down the new marriage. Think about justice in practical terms too: how will you divide maintenance and time between two countries? Your wife in your home country is still entitled to maintenance and attention. Ask the state Islamic religious affairs office and your embassy which documents are needed before going any further. See cross-border marriage.