What is Trojan.Agent?

Trojan.Agent is a general term MBAM and a few other security packages use to specify a "generic" trojan. It's hard to say how much damage it did (if any)...but IMHO I wouldn't worry about it since it's a fairly common low risk infection.

Probably no reason to be worried. 

And if you have a good firewall.... I probably wouldn't worry at all. 

There are much worse things you can get on your computer.....

Often times when you do scans, (I have never used the Malwarebytes software that you are using so I don't know if this can be done on it), but there is a way to find which directory the file is in, and also the file name.  Often times something.exe, or something.tmp, etc.   If you search the file name in google you can get much more information on exactly how serious a threat is.....

Yah, it was C:\Program Files\Internet Explorer\sxs.dll. But a Google search just showed me a load of logs other people had posted.

Probably from the kind of thread where someone says they have a problem, one or two of the regulars ask him to download HijackThis and insert program here and that other thing and post the 10-page logs, then the original poster comes back, posts a page of logs, and no-one ever ever replies.

Probably not, however.. please be advised that if you are using generic trojans there is a substantial increase in the risk of breakage.

I've never known anyone to have to change their bank cards and passwords due to pregnancy but there is no law opposing such action that I know of.

One thing to keep in mind is that these 'generic' Trojans can be modified by hackers... and might be a problem that just hasn't been recognized and received a special name just yet.