Avast WEBforum

Other => Viruses and worms => Topic started by: luisisrael on September 25, 2011, 02:51:56 AM

Title: Win32:Malware-gen: Avast keeps finding this malware
Post by: luisisrael on September 25, 2011, 02:51:56 AM
Avast finds that file " C:\windows\assembly\GAC_32\Desktop.ini " is infected by Win32:Malware-gen.[/font][/font][/font]
(it always appears duplicated in the scan log). If I try anything else but excluding the infected files it avast show a message of "access error (5)".
But even if I exclude them and make a scan at boot mode, this infected file is found again exactly the same way after some time.

I already used Malwarebytes to scan and remove malwares (many were found). But even so the problem is not solved.

How to remove for good this Win32:Malware-gen?

Please help

Luis Santiago Israel
Title: Re: Win32:Malware-gen: Avast keeps finding this malware
Post by: Pondus on September 25, 2011, 03:14:19 AM
follow essexboys guide here and attach the logs  http://forum.avast.com/index.php?topic=53253.0

lower left corner > additional options > attach
if the logs are to big upload to  http://www.mediafire.com/   and post the download link here


essexboy will then have a look when he arrive here tomorrow
Title: Re: Win32:Malware-gen: Avast keeps finding this malware
Post by: luisisrael on September 25, 2011, 03:49:04 PM
Logs from the OTL after I made cleaning with Avast and Malwarebytes
Title: Re: Win32:Malware-gen: Avast keeps finding this malware
Post by: luisisrael on September 25, 2011, 05:12:14 PM
I am trying to scan with the aswMBR, but an error happens again and again.

avast! Antirootkit stopped working.
A problem made the program stop doing the scan.

my operational system is Windos 7 Home Premium 64 bit.
Title: Re: Win32:Malware-gen: Avast keeps finding this malware
Post by: essexboy on September 25, 2011, 05:19:56 PM
Hi whatever it is it is hidden well

Warning This fix is only relevant for this system and no other, using on another computer may cause problems

Run OTL
THEN

Download and Install Combofix

Download ComboFix from one of the following locations:

Link 1  (http://download.bleepingcomputer.com/sUBs/ComboFix.exe)
Link 2 (http://www.forospyware.com/sUBs/ComboFix.exe)

VERY IMPORTANT !!! Save ComboFix.exe to your Desktop *

 IMPORTANT - Disable your AntiVirus and AntiSpyware applications, usually via a right click on the System Tray icon. They may otherwise interfere with our tools. If you have difficulty properly disabling your protective programs, refer to this link here  (http://forums.whatthetech.com/How_Disable_your_Security_Programs_t96260.html&pid=494216#entry494216")

(http://img.photobucket.com/albums/v706/ried7/NSIS_disclaimer_ENG.png)

(http://img.photobucket.com/albums/v706/ried7/NSIS_extraction.png)

Notes:
1. Do not mouse-click Combofix's window while it is running. That may cause it to stall.
2. Do not "re-run" Combofix. If you have a problem, reply back for further instructions.

Please make sure you include the combo fix log in your next reply as well as describe how your computer is running now
Title: Re: Win32:Malware-gen: Avast keeps finding this malware
Post by: luisisrael on September 25, 2011, 11:47:24 PM
The computer seems to be working normally.

attached, the logs from OTL and then from ComboFix (the one at the end of the scan and fix and another which was created after the computer was restarted).
Combofix pointed that MacAfee was enabled, but I have already uninstalled this antivirus after I installed Avast. I even looked for any file with Macafee name and nothing was found. it is also not on the list of files at Control Panel.  so, I guess, no need for worries.

Anything else should be done?
Title: Re: Win32:Malware-gen: Avast keeps finding this malware
Post by: luisisrael on September 25, 2011, 11:51:31 PM
This was also at C:\
where combofix saved its log. I do not know if it was there before or Combofix also created this file.

Anyway. goes attached.

thank you for the help

Luis
Title: Re: Win32:Malware-gen: Avast keeps finding this malware
Post by: luisisrael on September 26, 2011, 12:58:56 AM
Oh no!
I made a complete scan with Avast again. and the same way C:\Windows\assemply\GAC_32\Desktop appears two times infected by Win32:Malware-gen_
and now a THIRD infected file was shown, which is
C:\_OTL\MovedFiles\09252011_194357\C_windows\assembly\GAC_32\Desktop.ini.

This third was easily isolated by avast. the other I can only exclude like before, but not isolate.
Title: Re: Win32:Malware-gen: Avast keeps finding this malware
Post by: essexboy on September 26, 2011, 11:40:52 AM
The one in the OTL files was one that we had allready moved - lets give combofix a shot at it

1. Close any open browsers.
2. Close/disable all anti virus and anti malware programs so they do not interfere with the running of ComboFix.
3. Open notepad and copy/paste the text in the quotebox below into it:
Quote
File::
C:\windows\assembly\GAC_32\Desktop.ini.

Save this as CFScript.txt, in the same location as ComboFix.exe
(http://img.photobucket.com/albums/v666/sUBs/CFScriptB-4.gif)

Refering to the picture above, drag CFScript into ComboFix.exeWhen finished, it shall produce a log for you at C:\ComboFix.txt which I will require in your next reply.
Title: Re: Win32:Malware-gen: Avast keeps finding this malware
Post by: luisisrael on September 26, 2011, 07:11:15 PM
Log is attached.

some information might be important.


Yesterday. right after my reply starting with "oh no!" avast requested to complete the scan by restarting the computer (to run a scan before windows is initialized).
During the scan the battery went down and the laptop was not connected properly to energy source. So it might have shut down during the scan (not sure. I was sleeping).

After I initialize it again there was a process of checking wheter there was any damage.
After opening windows again, two strange things happened.

The most relevant might be that there are now two files named desktop.ini at my desktop (and Combofix disappeared from the desktop).

Another thing is that the icons of some folders are displayed with a lock. (Folders C:\Documents and Settings C:\MSOCache C:\System Volume Information and E:\System Volume Information).

But the computer seems to be working normally. I ran another scan with avast, the same viruses as usual were found and isolated (or excluded in the case of desktop.ini at GAC_32). And then I followed your instructions to make this new log which is attached to the message.

Thank you. and I appreciate if you could keep helping.

Luis
Title: Re: Win32:Malware-gen: Avast keeps finding this malware
Post by: essexboy on September 26, 2011, 07:25:13 PM
Quote
The most relevant might be that there are now two files named desktop.ini at my desktop (and Combofix disappeared from the desktop).
Another thing is that the icons of some folders are displayed with a lock. (Folders C:\Documents and Settings C:\MSOCache C:\System Volume Information and E:\System Volume Information).
This is normal as they are hidden files that were revealed during the cleaning process, we will hide them again on completion

Is the desktop.ini causing any problems as that is just a text file ?
Title: Re: Win32:Malware-gen: Avast keeps finding this malware
Post by: luisisrael on September 26, 2011, 11:06:41 PM
It isnt causing any problem at all
Title: Re: Win32:Malware-gen: Avast keeps finding this malware
Post by: essexboy on September 27, 2011, 12:07:41 AM
Subject to no further problems   :)

I will remove my tools now and give some recommendations, but, I would like you to run for 24 hours or so and come back if you have any problems 

Now the best part of the day ----- Your log now appears clean  :thumbsup:

A good workman always cleans up after himself so..The following will implement some cleanup procedures as well as reset  System Restore points:

Run OTLRemove ComboFix

Run OTL and hit the cleanup button.  It will remove all the programmes we have used plus itself. 

We will now confirm that your hidden files are set to that, as some of the tools I use will change that
(http://users.telenet.be/bluepatchy/miekiemoes/images/javaicon.gif)
Your Java is out of date. Older versions have vulnerabilities that malware can use to infect your system.
Please follow these steps to remove older version of Java components and upgrade the application.

 Upgrading Java:
SPRING CLEAN

To manually create a new Restore Point
 Now we can purge the infected ones
Now that you are clean, to help protect your computer in the future I recommend that you get the following free programmes:
(http://img233.imageshack.us/img233/7729/mbamicontw5.gif)
Malwarebytes (http://www.malwarebytes.org/mbam-download.php).  Update and run weekly to keep your system clean

Download and install FileHippo update checker (http://www.filehippo.com/updatechecker/) and run it monthly it will show you which programmes on your system need updating and give a download link

It is critical to have both a firewall and anti virus to protect your system and to keep them updated. To keep your operating system up to date visit
To learn more about how to protect yourself while on the internet read our little guide  How did I get infected in the first place ? (http://www.geekstogo.com/forum/topic/225044-preventing-malware-and-safe-computing/)

Keep safe  :wave:
Title: Re: Win32:Malware-gen: Avast keeps finding this malware
Post by: luisisrael on September 27, 2011, 02:30:44 PM
Thank you so much.

untill now no problems. and avast did not find any virus.
thank for your tips and help.

could you please instruct me how to also unistall aswMBR? (as I used it in the beggining of the process)

again. thank you. :)
Title: Re: Win32:Malware-gen: Avast keeps finding this malware
Post by: essexboy on September 27, 2011, 03:09:12 PM
Just delete from the desktop as it does not install  ;D
Title: Re: Win32:Malware-gen: Avast keeps finding this malware
Post by: luisisrael on October 17, 2011, 03:14:38 PM
Hi Essexboy,

After you helped me elimitaning this win32 virus it somehow appeared again (so maybe it was just hidden).
I noticed you were out for a while (from 28th till 08th October) so I waited till now to write again.

Just like before, Avast from time to time finds this file DESKTOP.INI infected by Win32:Malware-gen.

But now from time to time Avast blocks automatically the activities of this Win32 virus and shows the message that a Threat was Detected, like this:

C:\Windows\assembly\tmp\800000c0.sys -> Win32:Malware-gen tryed to create or infect this file (and was stopped by Avast).

Also like before. After I scan and exclude the infected Desktop.ini there comes some clean logs. And then again the virus reappears.

How should I proceed?
Is it possible that this is a false positive?

Thank you

Luis Santiago Israel
Title: Re: Win32:Malware-gen: Avast keeps finding this malware
Post by: DavidR on October 17, 2011, 04:17:29 PM
It may have been as a result of how you got infected in the first place rather than this one being hidden.

So you should proceed as before, Download the latest OTL version, Run OTL and attach the logs and essexboy will take a look at them..
Title: Re: Win32:Malware-gen: Avast keeps finding this malware
Post by: essexboy on October 17, 2011, 08:57:28 PM
You have a choice of two possible infections here either zero access or conserv dependant on which it is will determine my approach

OTL will let me know which it is

Quote
After I scan and exclude the infected Desktop.ini
This is part of the infection
Title: OTL log part 1
Post by: luisisrael on October 18, 2011, 10:59:38 PM
Hello Essexboy,

follow attached OTL log - part 1
Title: part 2 - extras
Post by: luisisrael on October 18, 2011, 11:01:50 PM
log part 2 - Extras
Title: Re: Win32:Malware-gen: Avast keeps finding this malware
Post by: essexboy on October 18, 2011, 11:05:37 PM
I can see no sign of it there - lets do one further run with combofix, although I feel it will find nothing

Download and Install Combofix
 
Download ComboFix from one of the following locations:
Link 1  (http://download.bleepingcomputer.com/sUBs/ComboFix.exe)
Link 2 (http://www.forospyware.com/sUBs/ComboFix.exe)
 
VERY IMPORTANT !!! Save ComboFix.exe to your Desktop
 
* IMPORTANT - Disable your AntiVirus and AntiSpyware applications, usually via a right click on the System Tray icon. They may otherwise interfere with our tools. If you have difficulty properly disabling your protective programs, refer to this link here  (http://forums.whatthetech.com/How_Disable_your_Security_Programs_t96260.html&pid=494216#entry494216)
(http://img.photobucket.com/albums/v706/ried7/NSIS_disclaimer_ENG.png)

(http://img.photobucket.com/albums/v706/ried7/NSIS_extraction.png)

Notes:
1. Do not mouse-click Combofix's window while it is running. That may cause it to stall.
2. Do not "re-run" Combofix. If you have a problem, reply back for further instructions.

Please make sure you include the combo fix log in your next reply as well as describe how your computer is running now
Title: ComboFix log
Post by: luisisrael on October 18, 2011, 11:29:30 PM
Combofix log attached.
the computer is working normally.

ahoj
Luis
Title: Re: Win32:Malware-gen: Avast keeps finding this malware
Post by: essexboy on October 19, 2011, 07:33:50 PM
Just an ADS there which appeared to be from your bank - but it is something I will bear in mind next time I see it

Once you are happy run the cleanup routine again