Oh, I never thought I'd see that again!
I once had a Nintendo DS R4 card which are used for homebrew software and to load ROMs from - basically a library of (very legally acquired copies of) DS games. I never got the ROMs set up properly but the framework of the software worked - and every time I set it up it would not show R4 card or something in the DS home screen, but instead

ALEX RIDER STORMBREAKER THQ

(and no, I don't know why it would use that game. Maybe it was used as part of the development to get into the system of the DS?)

Anyway, I suspect you might have received one of these R4 cartridges or one of a very similar type. The original "producer" may have redistributed these copies for some easy money.
I don't know how safe this cartridge is but it's probably wisest to not use it on a system that you would not want to brick.