I am getting a virus alert from Avast saying "A Trojan Horse Was Found" whenever I try to open a webpage

If problem persists, use Smitfraudfix or FixIEDef.


1.  Please download SmitfraudFix, and select Option 2. Clean (Safe mode recommended)
http://siri.geekstogo.com/SmitfraudFix.php


2.  Download FixIEDef by ShadowPuterDude to the Desktop.
http://downloads.malwareteks.com/FixIEDef.exe

You need to first Disable real-time protections that can interfer with FixIEDef:
Windows Defender, SUPERAntsipyware, Spybot's Tea Timer, etc.

Double-click FixIEDef
Click 'OK'
Click 'Scan'
Click 'OK' FixIEDef requires Adminstrator Privileges to run correctly. This box tells you that FixIEDef successfully elevated it's privileges to that of Administrator.
Wait for the scan to finish. It won't take very long.

WARNING: FixIEDef will kill all copies of Internet Explorer and Explorer that are running, during removal of malicious files. The icons and Start Menu on your Desktop will not be visible while FixIEDef is removing malicious files. This is necessary to remove parts of the infection that would otherwise not be removed.

Hi there b_haynes!  nice to see you, :)


Shashank,
That's right, it is never good to have 2 antivirus running in the system, it can only cause lockups and inefficiency to protect the system, not to mention it's a waste of resources.
Similar also applies with anti-spyware, it is not a good idea to have 2 anti-spyware running with both having a real-time protection.
But it is okay to have 2 anti-spyware installed( I have both Spybot and SUPERAntispyware and also MBAM at some stage) but only one should have a real-time protection, the other one can be used as an on-demand scanner which works extremely well with SUPERAntispyware as updates are free.


And if you ask whether having 2 antivirus with only one having a real-time protection okay?
No, that is still not good, an online scan is the better way of checking what your resident antivirus may have missed than installing a second antivirus.

 
>>>Should I uninstall my Avast first before installing FixIEDef or Malwarebytes (because Avast also has some Malware detection features)? Is it safe to delete files from the "%temp%" folder?< <<
No you don't need to uninstall Avast to run FixIEDef or MBAM, you just need to disable it while running the scan.
Yes, it is safe to delete files inside the temp folders, it's advisable to clean out all your temp folders now and then.
The only time that you shouldn't delete files in the temp folders is when you just installed a program/or updates and you have not rebooted yet. But after you've rebooted it should be okay. Some tools/scanners also needs files from the temp folders while scanning but after you've done with the tool it is then safe to delete any files there.
 

>>> I have heard that a novice user should avoid using HijackThis.....<<<
Yes, a novice should be careful what entries to fix in Hijackthis as fixing a crucial entries that the system need could cause system instability or applications to stop running. But some entries in hijackthis are not so crucial e.g. R's, 09, 016 entries which can be safely fixed. You can also safely fixed an 04 lines if you want to stop certain programs from running at bootup, fixing their entries only disable them, it doesn't affect that particular program when you need to run it.

Here's a good Hijackthis tutorial if you like to check out.
http://www.bleepingcomputer.com/tutorials/tutorial42.html