Can Malware Jump Between 2 MX in Dual Boot?

[Madison]

The question is, what is actually the problem, what do you call "malware"?

So, basically I installed some files for KDE Plasma configuration. After that my Plasma got sluggish and would freeze completely and if I did reboot, my computer would start but no display. After some tries I got into my system and took out the important files out.(still many trapped inside)

I am not sure if the files which I download from the web caused it. But if this comes from the files I was afraid if it may harm my new installation of MX 21.3. Since it is on the dual boot with my previous MX install.

Hope, I have been able to clear some misconception. Also, please forgive my misuse of terminologies as I might get them mixed with Windows terminologies, since I migrated from it.

[CharlesV]

Most likely, you have just gotten some mismatched files or something that is not working properly and caused the issue.

However, if it would make you feel better, install clamav, update and run it looking at ALL partitions and see if it finds anything.

[AK-47]

Plasma 5.27 is quite sluggish on older hardware. I found the Wayland session is quite usable with Plasma 5.27, though I have heard of complaints when paired with some hardware and multiple monitors.
If you can provide your Quick System Info that could provide some clues as to what's going on, likely it could just be Plasma being Plasma.

Depending on how difficult it would be to recreate your previous configuration was like, I would be inclined to dump it and start from scratch. From my experience, KDE Plasma doesn't do well with previous configurations, and starting fresh often results in much better performance.