Backdoor.Hale

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Discovered: August 05, 2003
Updated: February 13, 2007 12:04:38 PM
Also Known As: BackDoor-ATM.dr [McAfee]
Type: Trojan Horse
Systems Affected: Windows


Backdoor.Hale is a package of programs that provide backdoor access to an infected computer. This threat includes a Backdoor Trojan detected as Backdoor.Padmin, an FTP server, and various system utilities.

The existence of a C:\Winnt\System32\Qossrv folder is an indication of a possible infection. Some variants use C:\Winnt\System32\Dhcp instead, but this folder may be present on uninfected computers.

There have been reports that this threat is distributed by exploiting the DCOM RPC vulnerability, described in Microsoft Security Bulletin MS03-026 . University domains have been heavily targeted.

Antivirus Protection Dates

  • Initial Rapid Release version August 06, 2003
  • Latest Rapid Release version August 08, 2016 revision 023
  • Initial Daily Certified version August 06, 2003
  • Latest Daily Certified version August 09, 2016 revision 001
  • Initial Weekly Certified release date August 06, 2003

Click here for a more detailed description of Rapid Release and Daily Certified virus definitions.

Writeup By: Heather Shannon

Discovered: August 05, 2003
Updated: February 13, 2007 12:04:38 PM
Also Known As: BackDoor-ATM.dr [McAfee]
Type: Trojan Horse
Systems Affected: Windows


NOTE: Symantec Security Response has received several variants of this backdoor package. Two such variants are described below, but other variants could appear that use different filenames and directories.

Version 1

The installer for this version is a self-extracting CAB archive. It may be found in the system folder as a file named Nx.exe.

When Backdoor.Hale is executed, it performs the following actions:

  1. Creates the folder, C:\Winnt\System32\Qossrv.

    NOTE: This path is hard-coded and is used for all the operating systems.

  2. Copies the following files into the above directory:
    • Aysshell.exe: A legitimate "At Your Service" utility from Prism Microsystems.
    • Cdir.txt: A harmless text file.
    • Csrss.exe: a Backdoor Trojan Horse detected as Backdoor.Padmin.
    • Firedaemon.exe: A legitimate FireDaemon utility (used to start service processes).
    • Libeay32.dll: A legitimate .dll file.
    • Mswinsck.ocx: A legitimate .ocx file.
    • Pskill.exe: A legitimate utility used to kill processes.
    • Secure.exe: Detected as Backdoor.Hale.
    • Servuperfcount.dll: A legitimate .dll file that Winmgnt.exe uses.
    • Setup.bat: A batch file detected as Backdoor.Hale.
    • Setup.pif: A harmless .pif file.
    • Ssleay.dll: A legitimate .dll file.
    • Winmgnt.exe: a Serv-U FTP server.
    • Winexplorer.dll: This is not a .dll, but a configuration file for the FTP server.
    • Wget.exe: A legitimate program to fetch files using HTTP.
    • "- V1.0D (Haley) -": A 0-byte file.

  3. Adds the value:

    "NTDLM" = "c:\winnt\system32\qossrv\csrss.exe"

    to the registry key:

    HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run

  4. Adds the value:

    "port" = "6351"

    to the registry key:

    HKEY_CURRENT_USER\Software\VB and VBA Program Settings\pAdmin\Settings

    to open port 6351.

  5. Removes the network shares listed on the computer.

  6. Uses Asyshell.exe to start the following services:
    • NTF (Winmgnt.exe)
    • NTS (Secure.exe)
    • NTP (Csrss.exe)

      NOTE: Some variants may use different names for the services.

  7. Opens ports 5555 and 48522 using Winmgnt.exe.


Version 2:

This variant is not known to use a self-contained installer, like Nx.exe in the previous version.

The infection is similar to Version 1, except the files are copied into these directories:

C:\Winnt\System32\dhcp:
  • Csrsslsrms.dll: A text file, not a dll.
  • Explorer.exe: A Serv-U FTP server, detected as Backdoor.Hale.
  • Fport.exe: A utility used to list the processes with open network connections.
  • Igfxtray.exe: Detected as Backdoor.Trojan.
  • Nc.exe: A network utility.
  • Ntlmconf.dll: A text file, not a dll.
  • Pskill.exe: A utility used to kill processes.
  • Pslist.exe: A utility used to list processes.
  • Rar.exe: An archive utility.
  • Reg.exe: A utility used to edit the registry.
  • Rmns.exe: Detected as Backdoor.Hale.
  • Service.exe: A utility used to start the service processes.
  • SystemUptimeLog.ocx: A log file.
  • Tar.exe: An archive utility.
  • Tlister.exe: A utility used to list processes.
  • Wget.exe: A utility used to fetch files using HTTP.
  • WinExplorer.dll: A configuration file, not a dll.

C:\Winnt\System32\restore:
  • Csrss.exe: Detected as Backdoor.Padmin.
  • MSWINSCK.OCX: A legitimate system file.
  • Pskill.exe: A utility used to kill processes.
  • Reg.exe: A utility used to edit the registry.
  • Service.exe: A utility used to start the service processes.
  • Binary.gif
  • Compressed.gif
  • Del.gif
  • Dir.gif
  • Folder.open.gif
  • Image1.gif
  • Image2.gif
  • Movie.gif
  • Pdf.gif
  • Script.gif
  • Sound2.gif
  • Tar.gif
  • Text.gif
  • Thumbs.db

There have also been reports of variants that install files in C:\Winnt\System32\config or C:\Winnt\System32\home; and other folder and file names may be used in the future.

Recommendations

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

  • Use a firewall to block all incoming connections from the Internet to services that should not be publicly available. By default, you should deny all incoming connections and only allow services you explicitly want to offer to the outside world.
  • 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.
  • Ensure that programs and users of the computer use the lowest level of privileges necessary to complete a task. When prompted for a root or UAC password, ensure that the program asking for administration-level access is a legitimate application.
  • Disable AutoPlay to prevent the automatic launching of executable files on network and removable drives, and disconnect the drives when not required. If write access is not required, enable read-only mode if the option is available.
  • Turn off file sharing if not needed. If file sharing is required, use ACLs and password protection to limit access. Disable anonymous access to shared folders. Grant access only to user accounts with strong passwords to folders that must be shared.
  • Turn off and remove unnecessary services. By default, many operating systems install auxiliary services that are not critical. These services are avenues of attack. If they are removed, threats have less avenues of attack.
  • If a 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.
  • Configure your email server to block or remove email that contains file attachments that are commonly used to spread threats, such as .vbs, .bat, .exe, .pif and .scr files.
  • Isolate compromised computers quickly to prevent threats from spreading further. 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.
  • If Bluetooth is not required for mobile devices, it should be turned off. If you require its use, ensure that the device's visibility is set to "Hidden" so that it cannot be scanned by other Bluetooth devices. If device pairing must be used, ensure that all devices are set to "Unauthorized", requiring authorization for each connection request. Do not accept applications that are unsigned or sent from unknown sources.
  • For further information on the terms used in this document, please refer to the Security Response glossary.

Writeup By: Heather Shannon

Discovered: August 05, 2003
Updated: February 13, 2007 12:04:38 PM
Also Known As: BackDoor-ATM.dr [McAfee]
Type: Trojan Horse
Systems Affected: Windows



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. Restart the computer in Safe mode or VGA mode.
  4. Run a full system scan and delete all the files detected as Backdoor.Padmin, Backdoor.Hale, or Backdoor.Trojan. Delete the C:\winnt\system32\qossrv directory and its contents, or other files listed in the "Technical Details" section.
  5. Delete the values that were added to the registry.
For specific details on each of these steps, read the following instructions.

1. Disabling 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:
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. Updating 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: These virus definitions are posted to the LiveUpdate servers once each week (usually on Wednesdays), unless there is a major virus outbreak. To determine whether definitions for this threat are available by LiveUpdate, refer to the Virus Definitions (LiveUpdate).
  • Downloading the definitions using the Intelligent Updater: The Intelligent Updater virus definitions are posted on U.S. business days (Monday through Friday). 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 the Virus Definitions (Intelligent Updater).

    The Intelligent Updater virus definitions are available: Read "How to update virus definition files using the Intelligent Updater" for detailed instructions.

3. Restarting the computer in Safe mode or VGA mode
  • For Windows 95, 98, Me, 2000, or XP users, restart the computer in Safe mode. For instructions, refer to the document, "How to start the computer in Safe Mode."
  • For Windows NT 4 users, restart the computer in VGA mode.


4. Scanning for and deleting the infected files
  1. Start your Symantec antivirus program and make sure that it is configured to scan all the files.
  2. Run a full system scan.
  3. If any files are detected as infected with Backdoor.Hale or Backdoor.Padmin, click Delete.
  4. Using Windows Explorer, delete the directory, C:\winnt\system32\qossrv or C:\winnt\system32\restore. Delete any files in C:\winnt\system32\dhcp, listed in the "Technical Details" section.


5. Deleting the values from the registry

CAUTION : 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 keys only. Read the document, "How to make a backup of the Windows registry ," for instructions.
  1. Click Start, and then click Run. (The Run dialog box appears.)
  2. Type regedit
    Then click OK. (The Registry Editor opens.)

  3. Navigate to the key:

    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run

  4. In the right pane, delete any value which refers to the backdoor files, for instance:

    "NTDLM"="c:\winnt\system32\qossrv\csrss.exe"

  5. Navigate to the key:

    HKEY_CURRENT_USER\Software\VB and VBA Program Settings\pAdmin\Settings

  6. In the right pane, delete the value:

    "port"="6351"

  7. Exit the Registry Editor.


Writeup By: Heather Shannon