Respondent newbie question. Downloading apk - safety

Go easy on me. I've been doing usertesting for just over a month, and made about 400 bucks. I finally got my first respondent job, and it is for testing a mobile game apparently.

They have asked me to download an apk file via one drive, all through respondent. Is this common? What are the safety risks? I'm just being careful, and want to know if this is normal procedure.

Thanks in advance.