Veljko Birmancevic and Jo Inge Berget scored in each half for Malmo, which missed plenty of chances to take a bigger lead against the Bulgarian champion.
The Portuguese securities market commission temporarily suspended trading of the shares of Benfica, following the arrest of its president.
Jose Mourinho's Manchester United will be looking to maintain their robust start to their Champions League campaign.
Manchester United's Champions League encounter with Benfica on Wednesday represents a resumption of hostilities with foes.
Mexico forward Raul Jimenez scored a 75th-minute winner and Benfica moved closer to its fourth straight Portuguese league title by defeating Rio Ave 1-0 on Sunday.