Analysis by: jasperma

 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

 OVERALL RISK RATING:
 REPORTED INFECTION:
 SYSTEM IMPACT RATING:
 INFORMATION EXPOSURE:

  • Threat Type: Spyware

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

This spyware is a variant of the info-stealing ZBOT/ZeuS malware family that aims to defeat the two-factor security authentication of banks using a ZeuS mobile malware, such as WINCE_ZBOT.B, to steal text messages from affected users' mobile devices.

To get a one-glance comprehensive view of the behavior of this Spyware, refer to the Threat Diagram shown below.

It is a counterpart of SYMBOS_ZBOT.B, BBOS_ZITMO.B, and WINCE_ZBOT.B, which are for devices running on Symbian OS, BlackBerry OS, and Windows Mobile, respectively.

This spyware may be dropped by other malware. It may be unknowingly downloaded by a user while visiting malicious websites.

It may be injected into processes running in memory.

It opens a random port to allow a remote user to connect to the affected system. Once a successful connection is established, the remote user executes commands on the affected system.

It attempts to steal sensitive online banking information, such as user names and passwords. This routine risks the exposure of the user's account information, which may then lead to the unauthorized use of the stolen data.

  TECHNICAL DETAILS

Ports: Random
File Size: 122,880 bytes
File Type: PE
Memory Resident: Yes
Initial Samples Received Date: 02 Mar 2011
Payload: Downloads files, Compromises system security

Arrival Details

This spyware may be dropped by other malware.

It may be unknowingly downloaded by a user while visiting malicious websites.

Installation

This spyware drops the following files:

  • %Application Data%\{random folder name 1}\{random file name}.exe - copy of itself
  • %Application Data%\{random folder name 2}\{random file name} - contains encrypted stolen data

(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Windows\Profiles\{user name}\Application Data on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Application Data on Windows NT, and C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000, XP, and Server 2003.)

It creates the following folders:

  • %Application Data%\{random folder name 1}
  • %Application Data%\{random folder name 2}

(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Windows\Profiles\{user name}\Application Data on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Application Data on Windows NT, and C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000, XP, and Server 2003.)

It is injected into the following processes running in memory:

  • ctfmon.exe
  • Dwm.exe
  • explorer.exe
  • rdpclip.exe
  • taskeng.exe
  • taskhost.exe
  • wscntfy.exe

It may be injected into processes running in memory.

Autostart Technique

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

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
{GUID} = "%Application Data%\{random folder name 1}\{random file name}.exe"

Other System Modifications

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

HKEY_CURRENT_USER\Software\Microsoft\
{random characters}

It creates the following registry entry(ies) to bypass Windows Firewall:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile\AuthorizedApplications\
List
%Windows%\EXPLORER.EXE = "%Windows%\EXPLORER.EXE:*:Enabled:Windows Explorer"

Backdoor Routine

This spyware opens a random port to allow a remote user to connect to the affected system. Once a successful connection is established, the remote user executes commands on the affected system.

Information Theft

This spyware attempts to steal sensitive online banking information, such as user names and passwords. This routine risks the exposure of the user's account information, which may then lead to the unauthorized use of the stolen data.

It accesses the following site to download its configuration file:

  • http://{BLOCKED}snow.ru/ajax.jsp?v=5

NOTES:

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

It retrieves the following information from the infected system:

  • Flash player data
  • FTP credentials
  • Internet session cookies
  • Personal certificates

Other Details

This spyware monitors the Internet Explorer (IE) activities of the infected system, specifically the address bar or title bar. It recreates a legitimate website with a spoofed login page if a user visits banking sites with certain strings in the address bar or title bar.

  SOLUTION

Minimum Scan Engine: 8.900
FIRST VSAPI PATTERN FILE: 7.870.01
FIRST VSAPI PATTERN DATE: 02 Mar 2011
VSAPI OPR PATTERN File: 7.871.00
VSAPI OPR PATTERN Date: 02 Mar 2011

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

Restart in Safe Mode

[ Learn More ]

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_CURRENT_USER\Software\Microsoft
    • {random characters}

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
    • {GUID} = "%Application Data%\{random folder name 1}\{random file name}.exe"
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\AuthorizedApplications\List
    • %Windows%\EXPLORER.EXE = "%Windows%\EXPLORER.EXE:*:Enabled:Windows Explorer"

Step 5

Search and delete this folder

[ Learn More ]
Please make sure you check the Search Hidden Files and Folders checkbox in the More advanced options option to include all hidden folders in the search result.
  • %Application Data%\{random folder name 1}
  • %Application Data%\{random folder name 2}

Step 6

Restart in normal mode and scan your computer with your Trend Micro product for files detected as TSPY_ZBOT.HQ. 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 7

Scan your computer with your Trend Micro product to delete files detected as TSPY_ZBOT.HQ. 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.


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