Windows Defender constantly flagging Brave cache

@Lindy,
I actually believe it is. This is malware not specific to Brave – see this thread here:

And my response to another user encountering this issue:
Thanks for reaching out to us with this.

So it looks like you got yourself a virus – no good!

To confirm, you already had and had been using Brave before it was flagged – that is, this isn’t the first time installing the browser?

If so, follow the steps outlined in the article I linked to above (I will provide some additional resources below as well) to remove the infection from your machine. Additionally, since the source of the virus is likely a webpage (or files downloaded from one), ensure that you don’t re-infect your PC by:

  • Taking note of recent sites wherein Shields are not active
  • Recently visited sites that fail to establish a secure connection
  • Recently visited sites that you downloaded files from

This will also help establish whether or not this is a hole/flaw in Brave and/or the Chromium engine, the work of a crafty malware author, or some other issue entirely.

See also:
https://www.pcmalwarerepair.com/how-to-remove-android-adware-agent-xyd-virus-from-pc
https://blog.malwarebytes.com/detections/android-adware-mobidash/