The mystery behind Chinese messages showed on Myanmar devices

February 17, 2021

During the past days, Qurium has received numerous reports that users of mobile devices and Smart TVs in Myanmar are receiving messages in Chinese. This is a compilation of some of the reports.

Case 1: Users of MPT (Myanma Posts and Telecommunications) sending a SMS message to the number 7979 receive the response:

偬敡獥⁥湴敲⁡⁶慬楤敹睯牤 or Please enter a valid keyword

Case 2: Users of Smart TVs are seeing menu options in Chinese.

Case 3: Facebook account appears in Chinese.

  • SMS to MPT
  • Facebook
  • Smart TV

Making sense of 偬敡獥⁥湴敲⁡⁶慬楤敹睯牤

After obtaining a hexadecimal copy of the text that appeared on mobile devices in Myanmar (screenshoots are not useful for this), we converted the text into UTF-16 encoding.

Conversion of Chinese characters in Unicode to UTF-16.

For example the ideograms 偬敡 are in UTF16 encoding 6c50 6165

Unicode Character 'LATIN SMALL LETTER L' (U+006C)
Unicode Character 'LATIN CAPITAL LETTER P' (U+0050)
Unicode Character 'LATIN SMALL LETTER A' (U+0061)
Unicode Character 'LATIN SMALL LETTER E' (U+0065)

These bytes 6C50 6165 are in Latin UTF-8 encoding lPae

The whole “Chinese message” (UTF16) converted to Latin encoding reads:

lPaeese tnrea v ladik yeowdr

The first word “lPaeese“, seems to reassemble the English word “Please” with a capital P as the beginning of a sentence. This finding gives us the hint that the “Chinese text” is encoded in UTF16-BE. BE stands for “Big Endian” meaning that the system stores the most significant byte of a word at the smallest memory address and the least significant byte at the largest.

Converting the text 偬敡獥⁥湴敲⁡⁶慬楤敹睯牤 from UTF16-BE to Latin (ISO-8859-1) results in: Please enter a valid keyword

How is this possible?

This effect is known as “Mojibake” and it takes place when there is a mismatch between the encoding and the rendering.

What about the smart-TV showing Chinese? One possible explanation could be related to a similar report that we found on Reddit.

According to the Reddit thread and other postings, if something blocks the servers fonts.googleapis.com or fonts.gstatic.com, the TV can not render icons properly.

We have not managed to reproduce this problem in a smart-TV, but the screenshots we have received seems to affect the YouTube Icons. If those Icons are loaded from an external server (TTF font), unexpected rendering issues could take place.

20191122_195949.jpg

Conclusions

While we can not verify each of the cases reported in social media, the presence of Chinese characters in the MPT response to SMS 7979 is the result of a wrong encoding error. The encoding error is triggered when “Burmese” text is sent to the CBRT (Caller Ring Back Tone).

According to MPT documentation, ring tome can be set by sending the message “send REG M to 7979“, invalid messages return the message: Please enter a valid keyword.

When an invalid message is sent to the CBRT with Burmese encoding, the error message is wrongly encoded as UTF16-BE.