abp=" " code being added

Hello,
I have a very annoying problem with strange code being added to my html.

I usually write new pages and post in text mode, but on the occasion when I change to visual mode, when I go back to text mode, a large amount of code has been added to my text.

This code is the form of abp=”1780″, with the number incrementing on each occurrence.

For example:

<p abp=”1737″>[/one_third][one_third]</p>

<ul abp=”1738″>
<li class=”icon” abp=”1739″><span abp=”1740″>Diagnostics</span>
<li class=”icon” abp=”1742″><span abp=”1743″>Environmental</span>

How can I stop this from happening? It takes me ages to delete it all, and then if I go to visual mode again, it all gets added back.

Any help would be most appreciated.