I don’t know if this is the same issue, but I just noticed a problem with pasted images this morning. If you look at the PNG file signature spec PNG Spec you will see the following:

and if you look at the signature of a pasted image saved by a previous version of Obsidian you will find this signature:

A pasted image saved by a the current version of Obsidian (v0.10.1) has the following signature:

The ef bf bd at the start of the file in the above image is the UTF-8 encoding of the Unicode character U+FFFD REPLACEMENT CHARACTER.
codepoint character listing
I’m still trying to figure out if this is something to do with a system level update or Obsidian itself. I’m running Manjaro KDE with the latest updates.
A reference to a similar problem: https://github.com/jembi/openhim-core-js/issues/171