WAP Push messages - what and why are they?

Question

I've recently noticed that my phone received a strange SMS from sender called "wap_push_si!".

Googling about this message provides that it might be some kind of cellular-network-carrier maintenance/update message, though some suspect that it might also be exploited to carry malicious links.

Anyway, I've been using CyanogenMod with Google's default Messenger (not Hangouts) app - and can't seem to find a way to disable those messages. They even don't really appear in the Messenger app's messages list, but I've noticed them using Android API to read my device's messages (where they seem to be empty).

So, my questions are:

1. What are these messages really for?
2. How (or should) can they be disabled in Google Messenger app / CyanogenMod?
3. Can it be related to my phone sometimes losing cellular-data connection (but can still send/receive sms and calls)?
4. If there's any link inside this special kind of message, might it be automatically opened (without any user interaction), thus compromising the phone?

Answer 1

I cannot answer all your questions, but I can tell you this, I was also getting a message regularly from WAP_PUSH_SI! with no content in it through my stock Samsung messages app. I would delete it and it would come back, even on airplane mode. So the problem and cause is from another app. That app is Google messenger. If you install a different sms app, then change the new app to your default sms app, then delete the google messenger app, you will never see this message again. I do not know why Google messenger is doing that, but I saw on a forum where someone has sent a complaint with a picture to Google regarding this issue. I know Wap_push_ is generally used to push some sort of promotion or advertising for paid products or services..it is all about money.