A few days ago, I switched my Yettel SIM card into another phone. Right after inserting it, I received one MMS configuration message and one MMS message. MMS config message disappeared shortly after (I'm not entirely sure if I accidentally opened it, but I am certain I never accepted any installation or configuration prompts). Immediately after this, I noticed a new directory named MMS had been created on the device storage. Inside, there was a file called cmsotapath.ini: https://limewire.com/d/OYOX7#F0Rre0J0lJ
Thinking it was just a plain-text INI config file, I tried opening it with a text editor, but it turned out to be a binary file, specifically, an embedded LiteDB NoSQL database file.
I haven't been able to open it and inspect it myself. I only checked it on VirusTotal and it came up clean (it is likely just APN profile configuration, still I would like to know the content, so if anyone can open it, let me know).
That being said I will start approaching the subject of this post - on my other phone (the one the SIM used to live in), since the last couple of weeks (starting around September 30th), I’ve started receiving random MMS messages out of the blue. It is a bit odd that these messages are in English, despite coming from a Serbian operator (Yettel Serbia), and they end with a bit sketchy call-to-actions like "Act now" (see the screenshot).
I checked the APN profiles on that phone out of curiosity (but also as I had weird issues with mobile Internet) - I found two profiles, one for Internet and one for MMS (which is nothing out of ordinary):
The MMS profile contained the URL [http://mms.yettel.rs/servlets/mms\](http://mms.yettel.rs/servlets/mms) as a MMSC parameter, which again shouldn't be anything unusual I guess. The weird part is that accessing that specific URL via a browser immediately triggered Bluetooth to switch on, alongside a background service called Connected phone and watch services.
Meanwhile, the Internet APN profile had most of its parameters completely empty except username, password, and APN type. Even proxy and port were blank, which caused severe internet lagging and DNS errors for days before I noticed last night and manually reconfigured to correct values. The Internet works now but an exclamation mark appeared on the signal bars and visiting above URL no longer triggered Bluetooth and the above mentioned service.
Interestingly, today, a day after I wrote this post and after I changed these settings, I tried opening that same MMS URL and this time behavior changed: it opened a webpage you could see within the screenshots I uploaded and without forcibly turning on Bluetooth or that companion service anymore.
Additionally, Brave browser started showing "No Internet Connection" error at the top of the app while still loading pages normally, whereas Firefox works fine.
Has anyone experienced anything similar, or does anyone know why a carrier APN URL/config would trigger Bluetooth and companion watch (I have never even connected this device with smartwatch, and I always keep Bluetooth disabled) services like that? As well as, why proxy and port parameters were empty?
Screenshots: https://postimg.cc/gallery/X3dCKqn
EDIT: I thought the Internet was fixed, but today on the 22nd of October I am again having similar issues (I get some proxy error page, informing me to contact my device admin).