What are `Zone.Identifier` files? [closed]

Question

I often see files named 'blabla.exe:Zone.Identifier' when monitoring I/O with Process Monitor.
The files are seen on network-drives.

• What are Zone.Identifier files?
• What does the colon mean in the filename?
• Is the colon related the file's extended attributes?
• How do I prevent these files from being created when I copy code files from Windows Explorer to a WSL directory?

Answer 1

The text after the colon is an identifier for an "Alternate Data Stream". ADS is used to store meta-information about the file. For example, the Zone identifier stores whether the file was downloaded from the internet.

Some specific info: About URL Security Zones, Zone.Identifier Stream Name

Best is to google around for more information. Eg. this, this and this.

Finally, here's Streams, the Sysinternals tool for ADS.