Friday, January 18, 2008

Music folder virus in your pen drive

Hello,

These USB drives are driving me crazy. Most of the times they carry unwanted guests (Virus files). Earlier it was Brontok (remember that 44 KB file, a folder with .exe extension). Now we can see Music folder in almost every pen drive.
What is it exactly?

hmmmmmm

I am not sure about what it is exactly, but few things i can tell you about it.
  1. If it is executed or if it has a presence in your system then it will do the followings:
    • It will create a 232 KB folder in your hard drive.
    • It will start a fake lsass.exe process, the origin of this process is C:\windows\system.
    • The original shell extension file exists in C:\windows\system32 folder.
    • You can delete the Music folder if this process is running but it will come back.
  2. Now simply do the following to kill this
    1. Kill the process lsass.exe in task manager which has user name as "Administrator" or "Your name"
    2. Delete file lsass.exe from C:\Windows\system.
    3. Now remove registry entry:
      • If you are running Windows 95/98/ME, this startup entry is being started via the Shell= line in the Windows\system.ini file.
      • If you are running Windows NT/XP/Vista/2000/2003, this startup entry is being started via the Shell= line in the registry key:
      • HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon\Shell
Once you do these steps. You can delete the Music folder and it won't come back.

Comments are welcome. You may seek help or reply me @ spgarg04@gmail.com

Tuesday, January 8, 2008

Can't view hidden files and folders?

I spent almost 4-5 hours struggling this problem, but finally figured it out.

Symptoms

  1. You can't see hidden files and folders, even if you try modifying registry.
  2. Whenever you double click on drive icon on My Computer, it takes some time to open and always opens in new window.
  3. Your PC becomes a little slower.
  4. The Process is packed and/or encrypted using a software packing process
  5. This Process Creates Other Processes On Disk
  6. This Process Deletes Other Processes From Disk
  7. Loads and Executes a System Driver File
  8. Writes to another Process's Virtual Memory (Process Hijacking)
  9. Registers a Dynamic Link Library File
  10. The Process is polymorphic and can change its structure
  11. Violates Prevx File Security Settings
  12. Executes a Process
  13. Adds a Registry Key (RUN) to auto start Programs on system start up
  14. The process hooks code into all running processes which could allow it to take control of the system or record keyboard input, mouse activity and screen contents
  15. Modifies Windows Initialization And System Settings Used On Start up
Causes
  1. This problem can be a caused by a backdoor/Trojan amvo.exe.
  2. amvo.exe is bundled with several other worms/files some of them are
    1. 80avp08.com
    2. dosocom.com
    3. usdeiect.com
    4. xfoolavp.com
    5. autorun.inf
    6. Nideiect.com
    7. u.bat etc.. (a list of files is available here )
  3. These files are stored on the directories i.e. C:\, D:\ etc. and also on C:\windows\system32\amvo.exe
  4. You wouldn't be able to delete any of these files. Not even in Safe mode because it adds a autorun registry which loads amvo on boot.
Solution

  1. KILL all the processes like AMVO.exe or AVPO.exe
  2. Type "msconfig" without quote in run and press Enter.
    1. Go to startup tab and uncheck any entry on amvo.
  3. Type "cmd" without quote in run
    1. type "d:" and then press Enter
    2. type autorun.inf and then press Enter
    3. a file will open in notepad. this would have the name of the .exe/.bat/.com file in it, which is mounted at the boot time.
  4. Type "regedit" without quote in run and press Enter.
    1. Press Ctrl+F and type amvo, do the search again and again and delete all the related entries.
    2. Press Ctrl+F and type u.bat, do the search again and again and delete all the related entries.
    3. Press Ctrl+F and type amva, do the search again and again and delete all the related entries. Generally it should be HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Shared Tools\MSConfig\startupreg\amva
    4. search for the registry of file name which was entered in autorun.inf and delete all entries.
Now restart the computer. and do the followings
  1. Go to regedit and then HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer \Advanced\Folder\Hidden\SHOWALL
  2. Double click on the entry called CheckedValue and replace the 0 with 1.
  1. Now Close all the windows and Press Ctrl+E to open the explorer.
  2. Enable the hidden option from the folder options.
  3. Delete all the malicious files as mentioned above.
  4. Your computer is now trojan free.
  5. Find all the amvo related files and delete them. (some of them are amvo0.dll, amvo1.dll etc.)
Prevention

Generally this Trojan travels through a USB drive. so better explorer USB drive rather than opening it.

Comments are welcome. You may seek help or reply me @ spgarg04@gmail.com





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