If the Malaysian passport holders want to apply visa at Vietnam Embassy, they should to know that:
Visa administrative Institution: Vietnam Embassy
Processing time: depends on you how fast you need. But for sure, you should make a call to Vietnam Embassy for details.
Required Documents: passport, money and 1 new envelope with stamp on it and your exact home address in order to avoid losing issues.
How to apply: please take a look at contact information of Vietnam Embassy below
EMBASSY OF VIETNAM IN KUALA LUMPUR, MALAYSIA
Address: No.4, Persiaran Stonor 50450, Kualar Lumpur, MALAYSIA
Phone: 60-3-21484858 | 21484534 | 21484036 | 21641909
Fax: 60-3-21483270 | 21636334