The term Malay here doesn't refer to Malay(sia) as a country, rather to Malay as a culture of ethnic Malay. This includes most of the western and central parts of Indonesia, western part (and some of the eastern part) of Malaysia, southern part of Thailand, Brunei and parts of Singapore.
In one episode Mio wakes up late because her alarm clock is not working and her mother goes to sepak takraw meet. What flashes in Mio's mind reveals her understanding about the sport. However, that might be the only thing she knows because she doesn't even respond to Yukko's morning greeting.
Reference to sepak takraw has been decided since Nichijou Prototype.
Good Morning. Yukko's default morning greeting.
Good Night. Mai's response to Yukko's morning greeting.
Selamat TinggalYukko, Mio, and Mai run towards a train that will depart soon. Yukko is the only one 'safe' while the other two look on from the other side of train door. Yukko says selamat tinggal with the last consonant l pronounced as ru(ル). This fact reveals that Yukko is not very proficient in Malay.
Bear as Beruang (in dispute)
There is a speculation about a Malay pun in Episode 2, Part 5. So far we have found no confirmation whether the pun was intentional and someone saw it simply as a straight Japanese pun:
While pocketing Mio's money, her elder sister said this phrase:
ある時くま、そしてある時もク-マ (aru toki wa kuma, soshite aru toki mo ku-ma = sometimes i'm a bear, other times i'm also a be-ar).
In Malay bear is beruang, while (noting ク-マ = ku-ma = be-ar) ber-uang means have money.
Putting these together, we'll have: "sometimes I'm a bear, other times I also have money".
Yoshino uttered the 2nd phrase at the time when she pocketed Mio's money.
So, is the pun intentional or a weird coincidence?
Bear as Have Money
There are ugly debates in the comments section, kindly ignore them
While above influences cannot be attributed to a single country, the following is decidedly Indonesian.
This Easter Egg was brought to light by user mikoo at animesuki forum. It appears in several forms throughout the series, like in episode 7 below: