PowerShell Prompt on My Screen – Possible Malware?

It sounds like you could be dealing with malware. I recommend posting a screenshot of the PowerShell window, as that could help diagnose the problem better. The link you mentioned is concerning, so the more detail we have, the easier it will be to troubleshoot.

If you've already done a Defender offline scan, that's a good step. In the future, keep an eye out for any strange startup programs or scheduled tasks that look unfamiliar. Tools like Task Scheduler can help monitor these, but make sure to familiarize yourself with their functions first.

Ah man, that sounds rough! It's definitely a good idea to stay vigilant. For now, try checking your Task Scheduler to see if anything suspicious is running at odd hours. If you’re not comfortable there, you might want to look into malware removal tools for a more thorough clean.