Why can’t I delete files from USB drive?

I have a USB drive that I had plugged into my Nvidia Shield to store media on but is now attached to my router.

There are a handful of music and movie files on there that I just can’t delete.

I have tried using mapping the drive in Windows but get a permissions error (says files are owned by Linux Root). I’ve now set up an old laptop with Linux Mint and mounted the drive using CIFS but still get a permissions error when I try to delete. sudo, chmod and chattr all seem to do nothing for these files.

Searching Stack Overflow has made me think they might have been written in a different filesystem to what I have currently mounted with (CIFS v3). How can I find out how these files were written and/or how can I delete them?


ls -la shows this:

-rwxrwxr-x 1 martin root    7676 Apr 27  2014  AlbumArt_{4D7F16F2-DC1D-480A-84D6-459D5543127E}_Large.jpg
-rwxrwxr-x 1 martin root    1954 Apr 27  2014  AlbumArt_{4D7F16F2-DC1D-480A-84D6-459D5543127E}_Small.jpg
-rwxrwxr-x 1 martin root    1954 Apr 27  2014  AlbumArtSmall.jpg
-rwxrwxr-x 1 martin root    7676 Apr 27  2014  Folder.jpg

Here is the output of lsattr

---------------------- ./AlbumArtSmall.jpg
---------------------- ./AlbumArt_{4D7F16F2-DC1D-480A-84D6-459D5543127E}_Large.jpg
---------------------- ./AlbumArt_{4D7F16F2-DC1D-480A-84D6-459D5543127E}_Small.jpg
---------------------- ./Folder.jpg

When I try$ rm -f AlbumArtSmall.jpg

I get:

rm: cannot remove './AlbumArtSmall.jpg': Permission denied