Here's a story,
I used to work IT at a Biotech (Pfizer) with lots of Dr.'s (researchers) from China. They would go home for vacation or for business, and after they would come back, their laptops would be completely jacked up with software, and this was really bizarre, because there were ample security measures.
The thing is, I was the person to provision those laptops using Pfizers imaging systems, and they were on complete lockdown. They were encrypted, monitored, and without Admin privileges of ANY kind, there was nothing that could be installed or altered.
In fact, I tried (with admin powers) to see what I could do to figure out loopholes or security issues--and man, the Pfizer imaging system was locked down. It was covered in anti-malware/spyware/virus software.
Yet, when they came back from China (the place I now live ironically), impossibly, there was ALL sorts of stuff installed on their systems. At the time, I didn't think anything of it---I figured it was just some bad luck with some malware at a web site, and also as an IT guy, you have to triage your work--easier to backup the data and reimage in 45 minutes, than to spend days trying to figure it all out.
But then it happened again, and again. Each time they returned, I would save their data and completely re-image the machine. To this day, I have no idea how it was done. I'm smart enough and I couldn't do it, at all.
Relationships were better with China back then, so nobody was on guard or suspicious, and my job was to just make sure people could do their work, not to waste time investigating anomalies.
Anyway--I changed my profession and I'm an English teacher in China now
go figure. I'll let someone else figure it all out, I traded in computers for children, who are much more entertaining.
--and man Huawei has some really nice hardware, so it's unfortunate (or inconvenient) that this happens while I'm here!