could my chromebook local file be copied by malware extension ?

[Sativa Pics]

hello, I'm starting this post because of a concern I have with my chromebook.

Yesterday I happened to see on my chromebook a kind of extension with a weird name, it was written in chinese.
I never saw it before and I uninstalled it right away and I powerwashed my chromebook. All my datas was delete within the powerwash but I had an external backup, so my data wasn't lost.....
And since the powerwash I tried to locate that extension (or app...or add-on....although it looked more like an extension) but without success. All I remember was the title of the extention was written in chinese.

* And here is my concern * ( and would like to ask you what do you tink of it) :

I had sensitive private datas locally on my download chromebook folder, which is data for my personal project. I'm building a website and had everything in my file locally on my chromebook, which is music I composed, logos that has to be copyrighted.... etc. My fear is ''could my project datas (music, visual....etc) be copied by this chinese extension ?? In other words, could this extension (or app) copy my data that was on my download local chromebook folder and my project be grabbed by this app or extension ?

Thanks in advance for your futur clarifications.

[Just an Eric]

Please provide more information about the extension like, where it is.