Yes, it really looks like a Trichosanthes!...I thought there were only four seeds (but in fact there are many more, packed in four clusters!!!).

Dear Rana,

It looks very similar to some Ternstroemia (Ternstroemiaceae- Pentaphylacaceae s.l.) fruits. Could you provide photos of leaves or another plant´s part?. The fruits of Ternstroemia I know, however, have seeds with red arils and pericarps not so red,

Best whishes,

José Grande._

May I know in which parts of Malaysia, you found it?  As I am based here, I would try to procure it and find it's whole taxonomy. 

I agree with Anshary, the plant is a cucurbit (Bali Melon) and belongs to the genus Trichosanthes.

"This fruit is found dangling in the lowland forests of Bali. From a distance, the plant resembles a Passiflora, with similar leaves, but upon closer inspection it clearly turns out to be a cucurbit. The fruits are ribbed, ovoid cylindrical and ripen a brilliant crimson red. They last for a very long time and are very showy, and even though they are probably not edible, the plant has potential as an ornamental for the tropical garden. The fruit would perhaps also make a beautiful additions to floral arrangements."

http://www.rarepalmseeds.com/pix/TriMel.shtml

However, to identify the plant to the species level, you need to provide some more info about its morpho-pomological characteristics.

Regards

Thank you very much Mr  Anshary and Prof. Shtayeh for your valuable answers. they are really very helpful, I checked the link  and it looks very similar.

Thank you again

it is seems that Trichosanthes species

Family I have no idea, but the monkeys and birds know their business.  The red must be warning coloration.  At least I wouldn't eat them before anyone else.

I agree that it is a Trichosanthes (Fam. Curcubitaceae). Some species of this genus are very appreciate in traditional medicine, but other are well known due to their high toxicity. If you have a picture of the leaves and flower, it is posible to identify the specie (maybe ....Trichosanthes tricuspidata? T. cucumeroides?)

It may be Trichosanthes cordata Roxb.

fruit globose red smooth.

Yes, it really looks like a Trichosanthes!...I thought there were only four seeds (but in fact there are many more, packed in four clusters!!!).

I don 't know

Yes, does seem like pepo of Trichosanthes

It seems like Trichosanthes quinquangulata of Cucurbitaceae family.