Malioboro is owned by the guy (a General in the Indonesian army if the legend is true) who owns Stadium. It means there is no rules that apply once you're inside, if you have the money. There are girls litterally everywhere, most of them half naked or stripping. Lots of clients too and I did see a few foreigners. It's a massage place but you can stay in the lounge bar if you prefer, with striptease and loud music.
Beware: You have Malioboro spa and Malio Club!
Malio Club is next to Malioboro spa, but it is different. In my opinion, if all you want is to drink a beer, then Malio Club is better: It is similar to Sun City, V2 or Play in Alexis. Very very fun but way too many hookers for me.
If you want to stay close from Malioboro, I recommend you to book the Grand Mercure Hotel on Jalan Hayam Wuruk. It is a perfect location for nightlife and only 15 minutes away from Plaza Indonesia.
Everyday, from 11am until late (3am usually)
Malioboro Hotel & Spa Jakarta
Jalan Gadjah Madah No. 13
Telephone. +62-21 638 50000
Fax: +62-21 633 7181
Website with good information about the facilities and prices: Malioboro Jakarta