> For the complete documentation index, see [llms.txt](https://hackerlab.gitbook.io/wiki.hackerlab.cz/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://hackerlab.gitbook.io/wiki.hackerlab.cz/web-pentesting/windows-forbidden-file-names.md).

# Windows Forbidden File Names

Usefull in webserver and path traversal testing.

MS recommends avoiding **these names followed immediately by an extension**; for example, \
`NUL.txt` is not recommended.

```
CON
PRN
AUX 
NUL 
COM1 
COM2 
COM3 
COM4 
COM5 
COM6 
COM7 
COM8 
COM9 
LPT1 
LPT2 
LPT3 
LPT4 
LPT5 
LPT6 
LPT7
LPT8
LPT9 
```