Analysis by: Christopher Daniel So
 PLATFORM:

Windows 2000, Windows Server 2003, Windows XP (32-bit, 64-bit), Windows Vista (32-bit, 64-bit), Windows 7 (32-bit, 64-bit)

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

  • Threat Type: Spyware

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

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

It executes the dropped file(s). As a result, malicious routines of the dropped files are exhibited on the affected system.

  TECHNICAL DETAILS

File Size: 430,592 bytes
File Type: EXE
Memory Resident: No
Initial Samples Received Date: 13 May 2014

Arrival Details

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

  • %User Temp%\{random folder}\{random file name}.exe

(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista and 7.)

It creates the following folders:

  • %User Temp%\{random folder}

(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista and 7.)

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
{random string} = ""%User Temp%\{random folder}\{random file name}.exe""

It registers its dropped component as a system service to ensure its automatic execution at every system startup. It does this by creating the following registry entries:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\{random file name 2}
Tag = "1"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\{random file name 2}
DisplayName = "{malware file name}.exe"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\{random file name 2}
Start = "0"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\{random file name 2}
ImagePath = "\SystemRoot\System32\Drivers\{random file name 2}.sys"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\{random file name 2}
Group = "Boot Bus Extender"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\{random file name 2}
Type = "1"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\{random file name 2}
ErrorControl = "0"

It registers its dropped component as a system service to ensure its automatic execution at every system startup. It does this by creating the following registry keys:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\{random file name 2}

Other System Modifications

This spyware adds the following registry keys:

HKEY_CURRENT_USER\Software\Microsoft\
{random key}

It adds the following registry entries:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile
DisableNotifications = "0"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile\GloballyOpenPorts\
List
5165:TCP = "5165:TCP:*:Enabled:TCP 5165"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile\GloballyOpenPorts\
List
4733:UDP = "4733:UDP:*:Enabled:UDP 4733"

Dropping Routine

This spyware drops the following files:

  • %System%\Drivers\{random file name 2}.sys

(Note: %System% is the Windows system folder, which is usually C:\Windows\System32.)

It executes the dropped file(s). As a result, malicious routines of the dropped files are exhibited on the affected system.

  SOLUTION

Minimum Scan Engine: 9.700
FIRST VSAPI PATTERN FILE: 10.728.05
FIRST VSAPI PATTERN DATE: 15 Apr 2014
VSAPI OPR PATTERN File: 10.729.00
VSAPI OPR PATTERN Date: 16 Apr 2014

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

Scan your computer with your Trend Micro product and note files detected as TSPY_ZBOT.SMJD

Step 3

Since this malware cannot be removed in normal and safe mode, it is necessary to restart using the Windows Recovery Console. To restart the system using the Windows Recovery Console:

• On Windows XP and Server 2003 systems:

  1. Click Start>Run. In the Open input box, type secpol.msc and press Enter.
  2. In the left panel, double-click Local Policies>Security Options.
  3. In the right panel, double-click Recovery Console: Allow floppy copy and access to all drives and folders.
  4. Select Enabled and click OK.
  5. Insert the Windows Installation CD into the CD drive, then restart your computer.
  6. When prompted, press any key to boot from the CD.
  7. On the main menu, type r to go to the Recovery Console.
  8. Type the number that corresponds to the drive and directory that contains Windows (usually C:\WINDOWS) and press Enter.
  9. Type the Administrator password and press Enter.
  10. In the input box, type the following then press Enter:
    SET AllowAllPaths = TRUE
    del "%System%\Drivers\{random file name 2}.sys"
  11. Type exit and press Enter to restart the system normally.

• On Windows Vista and 7 systems:

  1. Insert your Windows Installation DVD in the DVD drive, then Press the restart button.
  2. When prompted, press any key to boot from the DVD.
  3. Depending on your Windows Installation DVD, you might be required to select the installation language. Then on the Install Windows window, choose your language, locale, and keyboard layout or input method. Click Next, then click Repair your computer.
  4. Select Use recovery tools that can help fix problems starting Windows. Select your installation of Windows. Click Next.
  5. If the Startup Repair window appears, click Cancel, Yes, then Finish.
  6. In the System Recovery Options window, click Command Prompt.
  7. In the Command Prompt window, type the following then press Enter:
    del "%System%\Drivers\{random file name 2}.sys"
    (Note: In Windows 7, all local drives will be assigned one more than normal. For example, the C: drive becomes D:.)
  8. Type exit and press Enter to close the Command Prompt window.
  9. Click Restart to restart the system normally.

Step 4

Restart in Safe Mode

[ Learn More ]

Step 5

Delete this registry key

[ Learn More ]

=Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this only if you know how to or you can seek your system administrator’s help. You may also check out this Microsoft article first before modifying your computer's registry.

  • In HKEY_CURRENT_USER\Software\Microsoft
    • {random key}
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services
    • {random file name 2}

Step 6

Delete these registry values

[ Learn More ]

Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this only if you know how to or you can seek your system administrator’s help. You may also check out this Microsoft article first before modifying your computer's registry.

  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • {random string} = ""%User Temp%\{random folder}\{random file name}.exe""
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile
    • DisableNotifications = "0"
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\GloballyOpenPorts\List
    • 4733:UDP = "4733:UDP:*:Enabled:UDP 4733"
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\GloballyOpenPorts\List
    • 5165:TCP = "5165:TCP:*:Enabled:TCP 5165"

Step 8

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