All brands offer internationl warranty, you just have to pay for it
Some brands / models come standard with International warranty (e.g. Asus).
At least tell us where your cousin is going Some time it is better to buy at the destination country (cheaper, more choice ... ) rather than trying to look for laptops with International warranty in Malaysia.
Also, even if a model has international warranty, if the model / spec is not sold in the country where your cousin is going (even if the brand is there), your cousin may have to wait for spare parts for warranty claim.

Btw, is your cousin an engineering student? If yes, then he better bite the bullet and get some beefy i7 laptop