Antivirus Software Is Destroying My Computer

I'm not sure what exactly is causing this, but Windows Defender keeps popping
up messages like this:
"Application cannot be executed. The file wuauclt.exe is infected. Do you
want to activate your antivirus software now?"
When I click on it, it opens up something called "Antivirus Soft", which
pretty much tries to get me to buy it without solving anything.
"Antivirus Soft" icons keep multiplying (I've let it multiply up to fifteen
of them) on my notification area, but if I move my mouse over them, they all
disappear.
I cannot run any programs (i.e. Microsoft Word, Ultimate Zip, etc.), because
the same message keeps popping up that whatever application cannot be
executed, because the file is infected, do I want to activate my antivirus
software... yeah.
The only thing that works at least, thank goodness, is Firefox.

I've run my Windows Defender scan on my computer, but it tells me nothing is
wrong (when obviously something is).
When I tried downloading other virus/spyware/malware software, such as
Ad-Aware and Spybot, I AGAIN got the message that the application cannot be
executed.

So I'm in a bind. I can't do anything. I don't know if everything actually
IS infected or if my Windows Defender software has some kind of malware on it
- this "Antivirus Soft" thing, which I've never seen before - and I can't
seem to remove it anyway.
I can't uninstall programs either or use Task Manager...

Anyway, I'm not tech-savvy at all, so I would appreciate it if someone could
help me out... or if I should just head straight to the nearest computer
doctor...

Go here: http://www.malwarebytes.org/

Use the blue button on the left hand side to download the free program.

Once installed, 'Update' to current version.

Then run a 'full' scan.

No, it didn't work. The same thing happened when I tried installing other
malware software. The malware software couldn't be executed because the file
was "infected".

At this point, I'm pretty much resigned to shelling out the money to have
someone repair it, as this malware is specifically preventing me from using
software to remove it...
But thanks for the suggestion. :)

Your system is infected, that's for sure. If you can explore the
system you can backup any critical files you want to keep, not
programs, just images, data, etc. Then what you really need to do is
reinstall Windows on it. If you can do that yourself you will save the
money. Chances are, that's what the geeks are going to do anyway. A
clean install will be more trustworthy than an attempt to get rid of
this malware.

For future reference, I found this link useful

It looks like I have to do a bunch of other stuff before I can use the
Malwarebytes software, so I'll try this once I have access to another
computer and I'll report back. :)

Have you tried running Malwarebytes with Windows in Safe
Mode?

BTW, it would be beneficial if you'd quote the post you're
responding to. Or at least the relevant parts of it.

You could try running a antivirus rescue scanner from a WinPE boot disk.
Antivirus has a poor track record (< 20%) when it comes to current malware.
I have had better luck rescanning after a month. However, if it was my
computer I would back up my personal data and then wipe the entire drive
(including HPA or DCO, if any). Then reinstall. The only problem is, if
you backup to a USB thumbdrive or like that may be infected in the process.
So your fresh install will become reinfected when you restore your personal
data. A better approach would be to ZIP your personal data up and then
netcat the archive to another computer over the network. If you don't
understand what I am saying then, yes, you need to hire someone.

That's not Windows Defender; that's malware putting up that message.

If you want to do it yourself, download Malwarebytes on another computer and
copy it to a CD or memory stick or something and then install it on your
computer while in safe mode. If it's the infection I think it is, safe mode
is not affected. Then run Malwarebytes (without the update first) and clean
things out. Then go back to regular mode, run Malwarebytes again and update
it before scanning a second time.

That's now what *I* do. I remove these kinds of infections all the time
without reinstalling Windows. By all the time I mean well over 95% of the
time. It just takes some doing. It's such a hassle to reinstall programs and
try to get everything back to the way it was that I specialize in removing the
malware without reinstalling Windows.

Sometimes you need to use the installation disk and boot to the recovery
console or use an outside program (OS) such as BART-PE.

Typo. I meant to say that this is NOT what I do. Windows seldom needs to be reinstalled.

That's what I'm going to do (but Safe Mode with Networking).
However, Antivirus Soft is not letting me download anything onto my infected
computer, or run any programs I have, so I'm going to have to download rkill
and Malwarebytes on a friend's computer later and transfer it with a flash
drive to my computer...

Sorry for not quoting properly!

I'll wish you the best of luck Rebecca!

Have a 'play' by all means, but as someone else has mentioned you'll be
better off flattening your machine and re-installing Windows from
scratch. It doesn't take long and is good experience! :)

It might not work - from a USB drive or other.

I ran across a AV 2010 infected computer today, nothing would run (MBAM,
SBS&D, SAS, TRJ6.8.1).... Strange thing what that it only infected
domain user profiles, not the local admin/user profile - booted as local
admin in safe mode, edited registry, rebooted in safe mode + networking,
ran MBAM, it cleaned up some, rebooted - still hacked, could not open
Task Manager, anti-malware tools... Uninstalled Symantec Corp 10 AV.

Safe mode + networking again, installed Avira Antivir, set to highest
detection modes, did a full scan, removed several trojans, rebooted, ran
a full scan in normal mode, MBAM reinstall, update, run, removed about a
dozen thigns... Loaded and ran SBS&D, no signs of anything now...

3 Hours to clean a PC that could have been wiped and rebuilt in 2 hours.

I have the same thing on my computer and I just completed the steps from
Bleeping Computer website. No joy, when I went back into normal mode, here
came the Antivirus Soft and all its warnings. You can't run any of
antivirus, malware, spyware programs you have. It won't even let me update
my TrendMicro antivirus. I guess my next step is to completely wipe it
clean. I do have some personal files I would like to salvage but am afraid
the crap will come with them. Don't know what to do next. This only
happens when working in Internet Explorer. I can use Firefox just fine.

I don't know the internals of the infection but...

I think you can back up your personal data files "safely", probably to
a USB drive would be best. Once you have your backups done, dismount
the drive and unplug it.

Wipe your system and reinstall Windows.

Install your favorite A-V product and update its definition files.

Verify proper operation of the system and IE.

Plug in your USB chip and scan it with the A-V product.

Copy your backups back onto your system.

MalwareBytes will install in Safe mode and get the current database if you
invoke Safe mode with networking. Forget Trend. Trash it. Install Avast
when you're done. Run MalwareBytes at least twice to be sure it got
everything. Dunno why it happens; maybe MB uncovers some kind of layers of
malware or something, but sometimes you have to run it twice.

But in most cases MB will operate just fine in Safe mode no matter what the
malware says. The other day, "System Security" malware tried to tell me that
it couldn't launch MB, but MB was running right under the warning box!

It helps if you can roll back the registry MANUALLY (using an external boot
disk) back to at least a week before the infection. Remember to get all 5
files: system, security, software, sam, and default.

I've found that the latest malware will not let any of the major players
run at all, including MBAM.

Is rkill ineffective yet?

Copy MBAM.EXE to sominthing other like leythos.com
Then run leythos.com

Doesn't matter, name them anything, still won't run. Seen this on about
a dozen machines in the last 2 weeks.

I ran across that a couple times but not lately. I found that renaming the
installer and then renaming the real executable helps.

Then try rolling back the computers to way before the infection started.
Again, do it manually by copying the files since chances are that the malware
isn't going to allow you to use the restore tool.

So what can one do? It won't let me system restore. I was going to wipe it
clean, but I have to do that from Factory PC Restore that is also on my
computer and it won't let me do that either. This is my old desktop that I
have had for 5 or 6 years and if I made a restore CD when I got it, I don't
know where it is at this point. Whatever this thing is it has complete
control of my computer. It won't let me open anything, says files are
corrupt. TrendMicro Internet Security keeps blocking Win 3/Nugel.E virus
also. Can I do the PC Restore thing in Safe Mode?

I have had the same exact thing on my computer and I finally got rid of it
last night after three days. I had already run MalwareBytes several times
and rkill in safe mode with networking, but it would not find anything or
get rid of it. Every time I would reboot in normal mode it was back. Since
it wouldn't let me system restore, I decided to turn system restore off and
the Antivirus Soft crap just magically disappeared and I was able to run all
of my scans. My computer is now acting normal again. Don’t know if this will
work for you but fixed my problem. You might want to run the MalwareBytes in
safe mode a couple of times first.