TSPY_ZBOT.SMED

 Analysis by: Erika Bianca Mendoza

 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 arrives as an attachment to email messages spammed by other malware/grayware or malicious users. It may be unknowingly downloaded by a user while visiting malicious websites.

It is injected into all running processes to remain memory resident.

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.

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

  TECHNICAL DETAILS

File Size:

Varies

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

16 Aug 2011

Arrival Details

This spyware arrives as an attachment to email messages spammed by other malware/grayware or malicious users.

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

It may be downloaded from the following remote sites:

  • http://{BLOCKED}port-irs.com/report_00000700955070US.pdf.exe
  • http://{BLOCKED}ch.com/canceled_report_43893842.pdf.exe

Installation

This spyware drops the following files:

  • %Application Data%\{random letters 2}\{random letters}.{random letters} - encrypted file

(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 drops the following copies of itself into the affected system:

  • %Application Data%\{random letters 1}\{random letters}.exe

(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 letters 1}
  • %Application Data%\{random letters 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 all running processes to remain memory resident.

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 letters 1}\{random letters}.exe

Other System Modifications

This spyware adds the following registry keys:

HKEY_CURRENT_USER\Software\Microsoft\
{random}

It modifies the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings\
Zones\0
1609 = 0

(Note: The default value data of the said registry entry is 1.)

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings\
Zones\1
1406 = 0

(Note: The default value data of the said registry entry is 1.)

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings\
Zones\1
1609 = 0

(Note: The default value data of the said registry entry is 1.)

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings\
Zones\2
1609 = 0

(Note: The default value data of the said registry entry is 1.)

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings\
Zones\3
1406 = 0

(Note: The default value data of the said registry entry is 3.)

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings\
Zones\3
1609 = 0

(Note: The default value data of the said registry entry is 1.)

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings\
Zones\4
1406 = 0

(Note: The default value data of the said registry entry is 3.)

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings\
Zones\4
1609 = 0

(Note: The default value data of the said registry entry is 1.)

It also creates the following registry entry(ies) as part of its installation routine:

HKEY_CURRENT_USER\Software\Microsoft\
{random}
{random} = {hex values}

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

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile\AuthorizedApplications\
List
C:\WINDOWS\explorer.exe = C:\WINDOWS\explorer.exe:*:Enabled:Windows Explorer

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://{random}/news/?s={random numbers}

The downloaded file contains information where the malware can download an updated copy of itself, and where to send its stolen data.

Other Details

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

  SOLUTION

Minimum Scan Engine:

9.200

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.SMED

Step 3

Restart in Safe Mode

[ Learn More ]

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 letters 1}\{random letters}.exe
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\AuthorizedApplications\List
    • C:\WINDOWS\explorer.exe = C:\WINDOWS\explorer.exe:*:Enabled:Windows Explorer

Step 5

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.

HKEY_CURRENT_USER\Software\Microsoft\{random}

Step 6

Restore this modified 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\Internet Settings\Zones\0
    • From: 1609 = 0
      To: 1609 = 1
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\1
    • From: 1406 = 0
      To: 1406 = 1
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\1
    • From: 1609 = 0
      To: 1609 = 1
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\2
    • From: 1609 = 0
      To: 1609 = 1
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\3
    • From: 1406 = 0
      To: 1406 = 3
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\3
    • From: 1609 = 0
      To: 1609 = 1
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\4
    • From: 1406 = 0
      To: 1406 = 3
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\4
    • From: 1609 = 0
      To: 1609 = 1

Step 7

Search and delete this file

[ Learn More ]
There may be some files that are hidden. Please make sure you check the Search Hidden Files and Folders checkbox in the "More advanced options" option to include all hidden files and folders in the search result. %Application Data%\{random letters 2}\{random letters}.{random letters}

Step 8

Search and delete these folders

[ 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 letters 1}
%Application Data%\{random letters 2}

Step 9

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


Did this description help? Tell us how we did.