I've been hacked ! Help please!!

I'd install eset nod 32 on your server and run it, wordpress websites seem to get hacked quite often.

if i got problem like you, i just reinstall fresh wp from original source, but make sure got to this "/wp-admin/export.php" to backup article and page.. before do it..
for image just copy all folder in "wp-content/uploads" dir and upload one by one.. ( only master image )
installing avir in your host i think useless if they use hidden embed upload script also consume more resource..

Google disvowing tool is your friend for the spanish links, you may want to check your website for outdated plugins or bad code