Need help

I have a remote computer that runs the MICROS POS system for a restaurant. So it's hard to work on, since it's remote and needs to stay up. Someone got it infected a week ago with some nasty stuff and ComboFix was ran, along with MalwareBytes. I can't recall what the other tech found but it cleaned it up where it's at leats working now. Windows XP SP3 x32.

My issue is that this computer keeps trying to go to a website every 4 minutes. I can see it in our content filter.

Here is the log:

That is the MAC address of the computer.

I've reran ComboFix and MalwareBytes and everything comes up clean.

Any idea what is causing this? I had the local tech do a fixmbr on it with no changes.