Strange SPIP ghost URLs on my site?

Dear beautiful WordPress world, maybe you can help me out:

I recently noticed something strange in my dashboard. In my Google Analytics summary is a reference to content that is not mine, with links to a folder that, to all appearances, does not exist.

I’m not quite sure if my installation has been hacked (I was a bit slow in updating to 3.1.3) or if it’s just a weird glitch on my server.

My site is at https://www.jjtiziou.net
Wordpress is installed in a subfolder at https://www.jjtiziou.net/jj

The analytics reports are showing content entitled “Musique – Bleu Pétrole” (no idea what this is) in this URL:
https://www.jjtiziou.net/spip_2.1.2/spip.php?rubrique12=&var_mode=recalcul

Logging in using Transmit as my FTP app, I can’t find any sign of this “/spip_2.1.2” folder, even with “show invisible files”

A screenshot of my wordpress dashboard showing this is linked here.
(note: I’ve since updated to 3.1.3, same results persist)

A screenshot from Google Analytics showing the same thing and a couple other results in the same folder is linked here.

From what I gather, SPIP is a CMS that I’ve never installed, so I’m not quite sure if my server is haunted by the electronic ghost of this french flying squirrel or what. Any thoughts or suggestions?

Many thanks for your time and attention, and hope you’re having a lovely day.
-jj

Disclaimer 1: I am not a web or wordpress expert, so please let me know if I’m missing anything or can provide more info.

Disclaimer 2: I am not quite sure if this is a problem with WordPress, or my server. The friend who set up my installation and designed my theme seems to think it may be a problem for the host, since the folder in question is in the root, outside of my wordpress installation directory. The host comes back and says that it’s a problem in the code and that they can’t deal with it.