BKDR_GHOSTNET.L

October 09, 2012
 Analysis by: Sabrina Lei Sioting
 ALIASES:

Backdoor:Win32/Hupigon.CN (Microsoft), P2P-Worm.Win32.Palevo.cjkl (Kaspersky), BackDoor-DVB.gen.w (McAfee), Trojan.Win32.Redosdru.C (Sunbelt), Trojan W32/Swisyn.CB (Norman),

 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

 OVERALL RISK RATING:
 DAMAGE POTENTIAL:
 DISTRIBUTION POTENTIAL:
 REPORTED INFECTION:

  • Threat Type: Backdoor

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

This backdoor arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

However, as of this writing, the said sites are inaccessible.

  TECHNICAL DETAILS

File Size:

5,437,111 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

20 Jun 2012

Arrival Details

This backdoor arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

Installation

This backdoor drops the following copies of itself into the affected system:

  • %Windows%\Ball.exe

(Note: %Windows% is the Windows folder, which is usually C:\Windows or C:\WINNT.)

It drops the following component file(s):

  • %System%\ctfmon1.exe

(Note: %System% is the Windows system folder, which is usually C:\Windows\System on Windows 98 and ME, C:\WINNT\System32 on Windows NT and 2000, or C:\Windows\System32 on Windows XP and Server 2003.)

Autostart Technique

This backdoor adds the following registry entries to enable its automatic execution at every system startup:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
Ball = "%Windows%\Ball.exe"

Other System Modifications

This backdoor deletes the following files:

  • %System%\dllcache\ctfmon.exe

(Note: %System% is the Windows system folder, which is usually C:\Windows\System on Windows 98 and ME, C:\WINNT\System32 on Windows NT and 2000, or C:\Windows\System32 on Windows XP and Server 2003.)

It adds the following registry entries as part of its installation routine:

HKEY_LOCAL_MACHINE\SYSTEM\InfoTime
InfoTime = "{malware executed - yyyymmmdd}"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\Ball
Group = "{characters}"

It adds the following registry keys as part of its installation routine:

HKEY_LOCAL_MACHINE\SYSTEM\InfoTime

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\Ball

Other Details

This backdoor connects to the following possibly malicious URL:

  • {BLOCKED}52100.3322.org

However, as of this writing, the said sites are inaccessible.

  SOLUTION

Minimum Scan Engine:

9.200

Step 1

For Windows XP and Windows Server 2003 users, before doing any scans, please make sure you disable System Restore to allow full scanning of your computer.

Step 2

Identify and terminate files detected as BKDR_GHOSTNET.L

[ Learn More ]
  1. If the detected file is displayed in either Windows Task Manager or Process Explorer but you cannot delete it, restart your computer in safe mode. To do this, refer to this link for the complete steps.
  2. If the detected file is not displayed in either Windows Task Manager or Process Explorer, continue doing the next steps.

Step 3

Delete this registry key

[ Learn More ]

Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry. Before you could do this, you must restart in Safe Mode. For instructions on how to do this, you may refer to this page If the preceding step requires you to restart in safe mode, you may proceed to edit the system registry.

 
  • In HKEY_LOCAL_MACHINE\SYSTEM
    • InfoTime
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services
    • Ball

Step 4

Delete this registry value

[ Learn More ]

Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.

  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • Ball = "%Windows%\Ball.exe"

Step 5

Scan your computer with your Trend Micro product to delete files detected as BKDR_GHOSTNET.L. If the detected files have already been cleaned, deleted, or quarantined by your Trend Micro product, no further step is required. You may opt to simply delete the quarantined files. Please check this Knowledge Base page for more information.

Step 6

Restore this file from backup only Microsoft-related files will be restored. If this malware/grayware also deleted files related to programs that are not from Microsoft, please reinstall those programs on you computer again.

  • ϿstemϽllcache\ctfmon.exe


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