A new feature in Windows is the addition of the Windows Subsystem for Linux (WSL), which allows Linux distribution installs directly onto Windows. Ryuk’s authors are aware of this, and have added additional blacklists to prevent the encryption of these folders which would render the WSL unusable.
The List of blacklisted *NIX folders are:
• bin
• boot
• Boot
• dev
• etc
• lib
• initrd
• sbin
• sys
• vmlinuz
• run
• var