Database error looks like exploit attempt ?

[NetRover]

Hi there, I just wondered is anyone can tell me if this is an attempted exploit and is this anything to worry about.

I always keep up to date with license and patches.

Database error in vBulletin 3.8.4:

Invalid SQL:
INSERT INTO scwho VALUES
        (NULL,
        "
",
        "",
        ,
        ,
        );

MySQL Error  : You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '
        ,
        )' at line 5
Error Number  : 1064
Request Date  : Wednesday, October 28th 2009 @ 06:24:40 AM
Error Date    : Wednesday, October 28th 2009 @ 06:24:40 AM
Script        : xxxxxxxxxxxxxxxxxxx/cron.php?rand=1256711067
Referrer      : xxxxxxxxxxxxxxxxxxx/forumdisplay.php?f=23
IP Address    : 92.40.51.21
Username      : Unregistered
Classname    : vB_Database
MySQL Version :

[RS_Jelle]

It looks more like a problem with a plugin
There's no scwho table in a default vB installation.