MS-DOS help

[Lord]

I got a trojan on my computer that Norton anti-virus can't remove. The trojan also prevents me from using the system restore tool. However, I think that I should still be able to system restore through MS-DOS. I have a disk configured to run MS-DOS at startup. However, from there, what commands do I need to type in to restore the computer to yesterday or an earlier date?
All help is appreciated ASAP please...I really need to get some work done but can't with this stupid trojan.

[SpiritWarrior]

In WinXP you put in your OS CD and hit "R" after booting from the cd-rom drive. This brings up the recovery console, from there you can repair. There is a command to run system restore through Dos but it is far from perfect and will force a restore even if the registry is corrupt. I would try other options first. So try locate you OS CD and see what can be done.

[Lord]

I found the CD, but does anyone know the command for MS-DOS? I'd like to try that first.

[shamrock_uk]

If you're using Windows XP then it's likely DOS won't even recognise the filesystem and will be no use here.

SpiritWarrior is offering good advice - I would also recommend using the recovery console.

Could you tell us what the trojan is? (Norton will probably give it a name of sorts).

Also, I assume you're tried to do system restore in safe mode (press F8 before you get to the WinXP splash screen)?

Can you get to a safe mode desktop at all? If you can, then it's best to work from there I would have thought rather than try anything lower-level.

[ 10-15-2006, 06:15 PM: Message edited by: shamrock_uk ]

[Lord]

I can get to safe mode. SR does not work from there either.

No, Norton only identifies it as a Trojan. If I click on the link in the activity log that says "learn more about this trojan," then my computer freezes. The scan detects no trojan, but it is definitely still there. Whenever I start my computer, a hundred systemac (Norton) windows open up and it says "scanning." I have to close them with task manager.

edit: It's called the Bookmarker Trojan. I'll see if I can delete it manually from the registry.

[ 10-15-2006, 07:29 PM: Message edited by: Lord ]

[SpiritWarrior]

Does it say "System restore cannot protect your computer at this time please restart etc."? I had something similiar awhile back.

The recovery console is an MSDOS prog btw it just has more functionality. In safemode you can start up command prompt windows too from the desktop.

[Felix The Assassin]

Originally posted by Lord: I can get to safe mode. SR does not work from there either. No, Norton only identifies it as a Trojan. If I click on the link in the activity log that says "learn more about this trojan," then my computer freezes. The scan detects no trojan, but it is definitely still there. Whenever I start my computer, a hundred systemac (Norton) windows open up and it says "scanning." I have to close them with task manager. edit: It's called the Bookmarker Trojan. I'll see if I can delete it manually from the registry.

Are you sure it's "Bookmarker"? That is ancient history type stuff as far as modern attacks are concerned.

If it is, here is your technical data:

Discovered: December 20, 2003
Updated: February 8, 2006 05:17:55 PM ZW3
Type: Trojan Horse
Systems Affected: Windows 2000, Windows 95, Windows 98, Windows Me, Windows NT, Windows XP

Trojan.Bookmarker is distributed as an executable installer through Web browser exploits or downloaders.

When the installer program is executed, it does the following:

1. Creates the file, %System%\Msconfd.dll. This file has the hidden attribute.

Note: %System% is a variable. By default, this is C:\Windows\System (Windows 95/98/Me), C:\Winnt\System32 (Windows NT/2000), or C:\Windows\System32 (Windows XP).
2. Invokes the Msconfd.dll file by executing this command:

rundll32.exe msconfd,Restore


When the Msconfd.dll file is loaded, it does the following:

1. Adds the value:

"AppInit_DLLs"="msconfd.dll"

to the registry key:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Windows

so that the .dll file is loaded each time you start Windows NT/2000/XP.

2. Adds the value:

"Desktop" = "rundll32.exe %System%\msconfd.dll,Restore ControlPanel"

to the registry key:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\Curr entVersion\Run

so that the dll is loaded every time you start Windows.

3. Adds the value:

"Desktop" = ""

to the registry key:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\Curr entVersion\Explorer

Note: is generated from the system time.
4. Creates or overwrites the file, %System%\drivers\etc\hosts, with the text:

127.0.0.1 localhost

5. Adds the values:

"Start Page"="http:/ /webcoolsearch.com"
"Search Page"="http:/ /webcoolsearch.com"
"Search Bar"="http:/ /webcoolsearch.com"

to the registry key:

HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main

6. Adds the value:

"SearchURL"="http:/ /webcoolsearch.com"

to the registry key:

HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer

7. Adds the value:

"SearchAssistant"="http:/ /webcoolsearch.com"

to the registry key:

HKEY_LOCAL_MACHINE\Software\Microsoft\Internet Explorer\Search

8. Creates several links to pornographic Web sites in the Favorites folder, and in the Links folder within the Favorites folder.

9. If the Msconfd.dll is launched using the command:

"rundll32.exe ...\msconfd,Restore..."

the Trojan will return an error number, and Windows will display an error message indicating that the .dll initialization routine failed.


Recommendations

Symantec Security Response encourages all users and administrators to adhere to the following basic security "best practices":

* Turn off and remove unneeded services. By default, many operating systems install auxiliary services that are not critical, such as an FTP server, telnet, and a Web server. These services are avenues of attack. If they are removed, blended threats have less avenues of attack and you have fewer services to maintain through patch updates.
* If a blended threat exploits one or more network services, disable, or block access to, those services until a patch is applied.
* Always keep your patch levels up-to-date, especially on computers that host public services and are accessible through the firewall, such as HTTP, FTP, mail, and DNS services (for example, all Windows-based computers should have the current Service Pack installed.). Additionally, please apply any security updates that are mentioned in this writeup, in trusted Security Bulletins, or on vendor Web sites.
* Enforce a password policy. Complex passwords make it difficult to crack password files on compromised computers. This helps to prevent or limit damage when a computer is compromised.
* Configure your email server to block or remove email that contains file attachments that are commonly used to spread viruses, such as .vbs, .bat, .exe, .pif and .scr files.
* Isolate infected computers quickly to prevent further compromising your organization. Perform a forensic analysis and restore the computers using trusted media.
* Train employees not to open attachments unless they are expecting them. Also, do not execute software that is downloaded from the Internet unless it has been scanned for viruses. Simply visiting a compromised Web site can cause infection if certain browser vulnerabilities are not patched.

[Felix The Assassin]

There appears to be some alpha-numeric updates on this old horse. The "K" version was last reported conducting operations on or about 30 Jun 2006.

Here is the technical information, what it will-has-can do, and how to fix your rig.

I have not used M$ in over 9 months, my cetification is no longer current, and I no longer work as a team IT manager. Work at your own risk!

What appears to be the whammy on this one is more than likely you have infected or attempted to infect everybody you have ever had e-mail contact with. It also tells us what you have been doing from the source of attack, and the payload it carries.

*WARNING* If this is a corporate node you are doomed, no questions asked, pack your stuff and leave! If the IT department does not work 24/7, they will find this at first log-in.

If this is your personal or shared home rig, there may be some embarrasment headed your way, especially when an elder opens IE and finds new home-page, and new bookmarks!

Peace Out-Felix

Full info:

Trojan.Bookmarker.K
Category 1
Discovered on: June 29, 2006
Last Updated on: June 30, 2006 10:36:07 AM



Trojan.Bookmarker.K is a Trojan horse that modifies the Internet Explorer start page and adds bookmarks to the Favourites and desktop folders.



Type: Trojan Horse




Systems Affected: Windows 2000, Windows 95, Windows 98, Windows Me, Windows NT, Windows Server 2003, Windows XP





protection
# Virus Definitions (LiveUpdate™ Plus)


June 29, 2006
# Virus Definitions (LiveUpdate™ Daily)


June 29, 2006
# Virus Definitions (LiveUpdate™ Weekly)


July 05, 2006
# Virus Definitions (Intelligent Updater)


June 29, 2006

threat assessment

Wild

* Number of infections: 0 - 49
* Number of sites: 0 - 2
* Geographical distribution: Low
* Threat containment: Easy
* Removal: Moderate



Threat Metrics
Low Low Low

Wild:
Low


Damage:
Low


Distribution:
Low

Damage

* Payload Trigger: n/a
* Payload: Changes the Internet Explorer startup page and adds several bookmarks
o Large scale e-mailing: n/a
o Deletes files: n/a
o Modifies files: n/a
o Degrades performance: n/a
o Causes system instability: n/a
o Releases confidential info: n/a
o Compromises security settings: n/a

Distribution

* Subject of email: n/a
* Name of attachment: n/a
* Size of attachment: n/a
* Time stamp of attachment: n/a
* Ports: n/a
* Shared drives: n/a
* Target of infection: n/a

technical details

When Trojan.Bookmarker.K is executed, it perfoms the following actions:

1. Creates the following files:

* %UserProfile%\Desktop\BEST DATING SITE IN THE NET.lnk
* %UserProfile%\Desktop\BEST DATING SITES CATALOGUE.lnk
* %UserProfile%\Desktop\BEST ONLINE DATING CHAT ROOMS.lnk
* %UserProfile%\Desktop\BEST ONLINE DATING MAGAZINE.lnk
* %UserProfile%\Desktop\BEST ONLINE DATING WEBCAMS.lnk
* %UserProfile%\Favorites\BEST DATING SITE IN THE NET.lnk
* %UserProfile%\Favorites\BEST DATING SITES CATALOGUE.lnk
* %UserProfile%\Favorites\BEST ONLINE DATING CHAT ROOMS.lnk
* %UserProfile%\Favorites\BEST ONLINE DATING MAGAZINE.lnk
* %UserProfile%\Favorites\BEST ONLINE DATING WEBCAMS.lnk

Note:%UserProfile% is a variable that refers to the current user's profile folder. By default, this is C:\Documents and Settings\[CURRENT USER] (Windows NT/2000/XP).

2. Copies itself as the following file:

%System%\datingtool.exe

Note:%System% is a variable that refers to the System folder. By default this is C:\Windows\System (Windows 95/98/Me), C:\Winnt\System32 (Windows NT/2000), or C:\Windows\System32 (Windows XP).

3. Adds the value:

"ControlPanel" = "%System%\datingtool.exe internet.dll,Datingtool"

to the registry subkey:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\Curr entVersion\Run

so that it runs every time Windows starts.

4. Adds the value:

"Start Page" = "[http://]dating.enetcap.com/Datin[REMOVED]"

to the registry subkey:

HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main

to modify the Internet Explorer start page.

5. Sets the above registry entries every 60 seconds, in order to restore them in case the user overwrites them.

6. Opens a new Internet Explorer window with the following URL every 300 minutes:

[http://]dating.enetcap.com/Datin[REMOVED]

recommendations

Symantec Security Response encourages all users and administrators to adhere to the following basic security "best practices":

* Turn off and remove unneeded services. By default, many operating systems install auxiliary services that are not critical, such as an FTP server, telnet, and a Web server. These services are avenues of attack. If they are removed, blended threats have less avenues of attack and you have fewer services to maintain through patch updates.
* If a blended threat exploits one or more network services, disable, or block access to, those services until a patch is applied.
* Always keep your patch levels up-to-date, especially on computers that host public services and are accessible through the firewall, such as HTTP, FTP, mail, and DNS services (for example, all Windows-based computers should have the current Service Pack installed.). Additionally, please apply any security updates that are mentioned in this writeup, in trusted Security Bulletins, or on vendor Web sites.
* Enforce a password policy. Complex passwords make it difficult to crack password files on compromised computers. This helps to prevent or limit damage when a computer is compromised.
* Configure your email server to block or remove email that contains file attachments that are commonly used to spread viruses, such as .vbs, .bat, .exe, .pif and .scr files.
* Isolate infected computers quickly to prevent further compromising your organization. Perform a forensic analysis and restore the computers using trusted media.
* Train employees not to open attachments unless they are expecting them. Also, do not execute software that is downloaded from the Internet unless it has been scanned for viruses. Simply visiting a compromised Web site can cause infection if certain browser vulnerabilities are not patched.

removal instructions

The following instructions pertain to all current and recent Symantec antivirus products, including the Symantec AntiVirus and Norton AntiVirus product lines.

1. Disable System Restore (Windows Me/XP).
2. Update the virus definitions.
3. Run a full system scan.
4. Delete any values added to the registry.

For specific details on each of these steps, read the following instructions.

1. To disable System Restore (Windows Me/XP)
If you are running Windows Me or Windows XP, we recommend that you temporarily turn off System Restore. Windows Me/XP uses this feature, which is enabled by default, to restore the files on your computer in case they become damaged. If a virus, worm, or Trojan infects a computer, System Restore may back up the virus, worm, or Trojan on the computer.

Windows prevents outside programs, including antivirus programs, from modifying System Restore. Therefore, antivirus programs or tools cannot remove threats in the System Restore folder. As a result, System Restore has the potential of restoring an infected file on your computer, even after you have cleaned the infected files from all the other locations.

Also, a virus scan may detect a threat in the System Restore folder even though you have removed the threat.

For instructions on how to turn off System Restore, read your Windows documentation, or one of the following articles:

* How to disable or enable Windows Me System Restore
* How to turn off or turn on Windows XP System Restore


Note: When you are completely finished with the removal procedure and are satisfied that the threat has been removed, reenable System Restore by following the instructions in the aforementioned documents.

For additional information, and an alternative to disabling Windows Me System Restore, see the Microsoft Knowledge Base article: Antivirus Tools Cannot Clean Infected Files in the _Restore Folder (Article ID: Q263455).

2. To update the virus definitions
Symantec Security Response fully tests all the virus definitions for quality assurance before they are posted to our servers. There are two ways to obtain the most recent virus definitions:

* Running LiveUpdate, which is the easiest way to obtain virus definitions:
o If you use Norton AntiVirus 2006, Symantec AntiVirus Corporate Edition 10.0, or newer products, LiveUpdate definitions are updated daily. These products include newer technology.
o If you use Norton AntiVirus 2005, Symantec AntiVirus Corporate Edition 9.0, or earlier products, LiveUpdate definitions are updated weekly. The exception is major outbreaks, when definitions are updated more often.
* Downloading the definitions using the Intelligent Updater: The Intelligent Updater virus definitions are posted daily. You should download the definitions from the Symantec Security Response Web site and manually install them. To determine whether definitions for this threat are available by the Intelligent Updater, refer to Virus Definitions (Intelligent Updater).

The latest Intelligent Updater virus definitions can be obtained here: Intelligent Updater virus definitions. For detailed instructions read the document: How to update virus definition files using the Intelligent Updater.


3. To run a full system scan

1. Start your Symantec antivirus program and make sure that it is configured to scan all the files.
* For Norton AntiVirus consumer products: Read the document: How to configure Norton AntiVirus to scan all files.
* For Symantec AntiVirus Enterprise products: Read the document: How to verify that a Symantec Corporate antivirus product is set to scan all files.
2. Run a full system scan.
3. If any files are detected, follow the instructions displayed by your antivirus program.


Important: If you are unable to start your Symantec antivirus product or the product reports that it cannot delete a detected file, you may need to stop the risk from running in order to remove it. To do this, run the scan in Safe mode. For instructions, read the document, How to start the computer in Safe Mode. Once you have restarted in Safe mode, run the scan again.

After the files are deleted, restart the computer in Normal mode and proceed with the next section.

Warning messages may be displayed when the computer is restarted, since the threat may not be fully removed at this point. You can ignore these messages and click OK. These messages will not appear when the computer is restarted after the removal instructions have been fully completed. The messages displayed may be similar to the following:

Title: [FILE PATH]
Message body: Windows cannot find [FILE NAME]. Make sure you typed the name correctly, and then try again. To search for a file, click the Start button, and then click Search.


4. To delete the value from the registry
Important: Symantec strongly recommends that you back up the registry before making any changes to it. Incorrect changes to the registry can result in permanent data loss or corrupted files. Modify the specified subkeys only. For instructions refer to the document: How to make a backup of the Windows registry.

1. Click Start > Run.
2. Type regedit
3. Click OK.

Note: If the registry editor fails to open the threat may have modified the registry to prevent access to the registry editor. Security Response has developed a tool to resolve this problem. Download and run this tool, and then continue with the removal.

4. Navigate to the subkey:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\Curr entVersion\Run

5. In the right pane, delete the value:

"ControlPanel" = "%System%\datingtool.exe internet.dll,Datingtool"

6. Navigate to the subkey:

HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main

7. In the right pane, delete the value:

"Start Page" = "[http://]dating.enetcap.com/Datin[REMOVED]"

8. Exit the Registry Editor.