Xiaomi/MIUI builtin Avast broken?

Avast Mobile Security Avast Mobile Security for Android
1

Xiaomi uses a bulitin avast scanner in its MIUI. I downloaded the eicar testvirus (which is a harmless test signature to check if the scanners are working) at http://www.eicar.org/86-0-Intended-use.html on a Xiaomi Note 4 (8.5.4.0 NCFMIED) and run the builtin virus scanner with the avast engine. It reported that all is ok. The eicar file hasn’t been found.

After that I installed the “official” Avast Mobile Security app, run a scan and the eicar file has been found and reported as a virus/malware.

You can see it in this video:
https://youtu.be/4CwGIBg0yWo

Can someone tell me why the builtin avast doesn’t recognize the eicar file?

2

You should ask Xiaomi as they are the ones who installed that version.

3

Hi,

from the screen capture it seems that the Xiaomi implementation only scans installed apps on the device, whereas AMS by default scans also files on the internal storage (i.e. the eicar file is stored on the local storage in “Downloads” folder).

Regards,
Ondrej