How was I hacked?
 

One of my sites was hacked last week and then again the other day.

I was running vB 3.8.4 at the time and I've managed to upgrade to vB 3.8.5 now, which I'm hoping has plugged the hole.

However, I thought it would be prudent to verify that this was a vulnerability in 3.8.4 and not a problem with something else on my site.

The hacker was able to insert some code into the footer template on my site to execute some JavaScript which added a hidden iframe directed to an external site.

HTML Code:

Is this a known exploit in the base v3.8.4 vBulletin code?

How is it that the attacker was able to update the database to insert this code into the footer template?

If I can understand the attack vector, I stand a better chance of identifying any other weaknesses on my site.