I found this cropping up all of a sudden on all the pages / posts on one of my sites.
Not Found The requested URL /linkr/get/ was not found on this server. Apache/2.2.3 (CentOS) Server at xxx.xx.xx.xx Port 80
I also found a load of injection links hidden in the header.php file on the same site, which I manually removed.
I had a look in the footer.php file and found this piece of code at the bottom of the file:
<?php
error_reporting(0);
include ('foter.php');
?>
I also found the file "foter.php" in the theme directory (clever huh? looks like footer.php). Anyway, neither the bit of code or the foter.php file were in the original theme files.
I deleted the code above and the foter.php file and the unwanted wording went away.
My guess is that it is related to the injected links in the header.php file - although they could be separate issues.
Of course some toxic bot must have put it there in the first place and so simply removing it is only going to deal with the symptom. I am going to go through the site with a fine tooth-comb and the previous advice about file access permissions would seem to be a good place to start.