Backdoor.Hatckel

SUMMARY

Backdoor.Hatckel is a backdoor Trojan that gives an attacker unauthorized access to an infected computer. By default it opens 15 ports on the infected computer: 1101 to 1115. Backdoor.Hatckel is written in Visual Basic.

Protection

• Virus Definitions (LiveUpdate™ Weekly) December 6, 2002
• Virus Definitions (Intelligent Updater) December 5, 2002

Threat Assessment

Wild

• Wild Level: Low
• Number of Infections: 0 - 49
• Number of Sites: 0 - 2
• Geographical Distribution: Low
• Threat Containment: Easy
• Removal: Moderate

Damage

• Damage Level: Medium
• Modifies Files: Modifies the registry.
• Compromises Security Settings: Allows unauthorized access to the compromised computer.

Distribution

• Distribution Level: Low
• Ports: 1101; 1102; .. 1115 (15 ports)

TECHNICAL DETAILS

When Backdoor.Hatckel runs, it performs the following actions:

It creates the value

Runths    <Trojan path and file name>

in the registry key

HKEY_LOCAL_MACHINESOFTWAREMicrosoftWindowsCurrentVersionRun

so that the Trojan starts when you start Windows.

It creates or modifies the values

Search Page    http:/www.telhack.org
Söksida    http:/www.telhack.org
Startsida    http:/www.telhack.org

in the registry key

HKEY_CURRENT_USERSoftwareMicrosoftInternet ExplorerMain

If the operating system is Windows 95/98/Me, Backdoor.Hatckel attempts to obtain access to the password cache that is stored on the local computer. To notify the client side, the Trojan uses ICQ pager notification. The remote commands that are accepted by Backdoor.Hatckel can perform the following actions:

• Install an FTP server which allows the hacker to use the infected computer as a temporary storage device
• Play sounds, perform various annoying actions, change system parameters, and cause system instability
• Inventory processes and active windows
• Restart the operating system
• Open the Web browser to a given URL
• Report the battery status of the infected computer (If the computer uses a battery)

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

NOTE: These instructions are for all current and recent Symantec antivirus products, including the Symantec AntiVirus and Norton AntiVirus product lines.

1. Update the virus definitions.
2. Run a full system scan and write down the name of the Trojan. In most cases, you will not be able to delete it at this time.
3. Do one of the following:
   • Windows 95/98/Me: Restart the computer in Safe mode.
   • Windows NT/2000/XP: End the Trojan process.
4. Run a full system scan, and delete all files that are detected as Backdoor.Hatckel.
5. Reverse the changes that the Trojan made to the registry.
   

For details on how to do this, read the following instructions.

To update the virus definitions:
All virus definitions receive full quality assurance testing by Symantec Security Response before being posted to our servers. There are two ways to obtain the most recent virus definitions:

• Run LiveUpdate, which is the easiest way to obtain virus definitions. These virus definitions are posted to the LiveUpdate servers once each week (usually Wednesdays) unless there is a major virus outbreak. To determine whether definitions for this threat are available by LiveUpdate, look at the Virus Definitions (LiveUpdate) line at the top of this write-up.
• Download the definitions using the Intelligent Updater. Intelligent Updater virus definitions are posted on U.S. business days (Monday through Friday). They must be downloaded from the Symantec Security Response Web site and installed manually. To determine whether definitions for this threat are available by the Intelligent Updater, look at the Virus Definitions (Intelligent Updater) line at the top of this write-up.
  
  Intelligent Updater virus definitions are available here. For detailed instructions on how to download and install the Intelligent Updater virus definitions from the Symantec Security Response Web site, click here.

To scan for and list the infected files:

1. Start your Symantec antivirus program, and make sure that it is configured to scan all files.
   • Norton AntiVirus consumer products: Read the document How to configure Norton AntiVirus to scan all files.
   • Symantec enterprise antivirus products: Read the document How to verify a Symantec Corporate antivirus product is set to scan All Files.
2. Run a full system scan.
3. If any files are detected as infected with Backdoor.Hatckel, write down the names of the infected files. You can try to delete them at this time, but this will fail if the Trojan is running in memory.

To restart the computer in Safe mode or end the Trojan process:

• Windows 95/98/Me
  Restart the computer in Safe mode. All Windows 32-bit operating systems, except for Windows NT, can be restarted in Safe mode. For instructions on how to do this, read the document How to start the computer in Safe Mode.
  
• Windows NT/2000/XP
  To end the Trojan process:
  1. Press Ctrl+Alt+Delete once.
  2. Click Task Manager.
  3. Click the Processes tab.
  4. Double-click the Image Name column header to sort the processes alphabetically.
  5. Scroll through the list, and look for the file name that was detected as infected by the Trojan.
  6. If you find the file, click it, and then click End Process.
  7. Exit the Task Manager.

To scan for and delete the infected files:

1. Start your Symantec antivirus program, and make sure that it is configured to scan all files.
   • Norton AntiVirus consumer products: Read the document How to configure Norton AntiVirus to scan all files.
   • Symantec enterprise antivirus products: Read the document How to verify a Symantec Corporate antivirus product is set to scan All Files.
2. Run a full system scan.
3. If any files are detected as infected with Backdoor.Hatckel, click Delete.

To reverse the changes that the Trojan made to the registry:

CAUTION: Symantec strongly recommends that you back up the registry before you make any changes to it. Incorrect changes to the registry can result in permanent data loss or corrupted files. Modify only the keys that are specified. Read the document How to make a backup of the Windows registry for instructions.

1. Click Start, and click Run. The Run dialog box appears.
2. Type regedit and then click OK. The Registry Editor opens.
3. Navigate to the key
   
   HKEY_LOCAL_MACHINESoftwareMicrosoftWindowsCurrentVersionRun
   
4. In the right pane, delete the value
   
   Runths    <Trojan path and file name>
   
5. Navigate to the following key:
   
   HKEY_CURRENT_USERSoftwareMicrosoftInternet ExplorerMain
   
6. In the right pane, restore the following value to its original settings:
   
   Search Page
   
   For example, you may restore it to the following setting, which is used by default:
   
   Search Page     http://www.microsoft.com/isapi/redir.dll?prd=ie&ar=iesearch
   
7. Next, delete the following values in the right pane of the same key:
   
   Söksida       http:/www.telhack.org
   Startsida     http:/www.telhack.org
   
8. Exit the Registry Editor.