Hi!
[[ebx]] smells like some sort of pointer management, hmm, are / were you got inspired by C or C++?
Cool!
No, it looks like it is not supported, but you can do it manually.
Don't blame NASM, it can do magic.
Seems that it is not even supported at machine language level.
I haven't seen such addressing mode, I would call it - pointeristic addressing mode.
But there is a solution - assemblistic version:
mov ebx,[ebx]
mov ebx,[ebx]
OR, in a single line - bytistic version:
db 0x67,0x8b,0x1b,0x67,0x8b,0x1b
Bye,
Encryptor256's Investigation \ Research Department.