> this tunnel can be triggered from the cmdline with the portable version of code.exe. An attacker just has to upload the binary
If the attacker can run commands and upload binaries, it really doesn't matter what VS Code does. There are lots of commands and binaries that can open network connections.
Edit: The attacker apparently needs to control the URL and exfiltrate the activation code [0], so if they can already execute commands and open network connections, then this enables them to execute commands and open network connections. So, as mentioned by other commenters, this does sound a lot like Raymond Chen's airtight hatchway [1].
If the attacker can run commands and upload binaries, it really doesn't matter what VS Code does. There are lots of commands and binaries that can open network connections.
Edit: The attacker apparently needs to control the URL and exfiltrate the activation code [0], so if they can already execute commands and open network connections, then this enables them to execute commands and open network connections. So, as mentioned by other commenters, this does sound a lot like Raymond Chen's airtight hatchway [1].
[0] https://badoption.eu/blog/2023/01/31/code_c2.html
[1] https://devblogs.microsoft.com/oldnewthing/20060508-22/?p=31...