Threat Encyclopedia

TSPY_ZBOT.SMHA

Publish date: February 18, 2011

ANALYSIS BY

jasperm


PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

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

  • Threat Type:Trojan

  • Destructiveness:No

  • Encrypted: Yes

  • In the wild: Yes

OVERVIEW


This spyware has increased potential for damage, propagation, or both, that it possesses. Specifically, attempts to steal user information such as user names, passwords, and banking credentials.

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

This Trojan 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. It retrieves specific information from the affected system.

TECHNICAL DETAILS

Ports:

Random

File Size:

Varies

File Type:

PE

Memory Resident:

Yes

Initial Samples Received Date:

16 Feb 2011

Payload:

Drops files, Compromises system security, Modifies system registry

Arrival Details

This Trojan may be dropped by other malware.

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

Installation

This Trojan 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:\Documents and Settings\{user name}\Application Data on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Roaming on Windows Vista and 7.)

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:\Documents and Settings\{user name}\Application Data on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Roaming on Windows Vista and 7.)

It is injected into the following processes running in memory:

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

It may be injected into processes running in memory.

Autostart Technique

This Trojan 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 Trojan 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 Trojan 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 Trojan 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://www.{BLOCKED}ptbiz.ru/turkishxan.bin
  • http://{BLOCKED}orntonllp.com/IEupdater.bin

It retrieves the following information from the affected system:

  • Personal certificates (MY)
  • FTP credentials
  • Internet session cookies
  • Flash player data

NOTES:
As of this writing, the said sites are inaccessible.

It monitors the Internet Explorer (IE) activities of the affected 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

VSAPI OPR PATTERN File:

7.843.00

VSAPI OPR PATTERN Date:

18 Feb 2011

Step 1

Before doing any scans, Windows XP, Windows Vista, and Windows 7 users must disable System Restore to allow full scanning of their computers.

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.SMHA. 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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