TSPY_ZBOT.YUT

 Analysis by: Michael Cabel

 PLATFORM:

Windows 2000, XP, 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 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 attempts to steal information, such as user names and passwords, used when logging into certain banking or finance-related websites.

It attempts to get information from a list of banks or financial institutions.

It checks for the presence of the following processes which are related to Outpost Personal Firewall and ZoneLabs Firewall Client:

  • outpost.exe
  • zlclient.exe

It terminates if either of the said processes exist. This is to ensure that it runs uninterrupted. It also has rootkit capabilities, which enables it to hide its processes and files from the user.

  TECHNICAL DETAILS

File Size:

134,656 bytes

File Type:

PE

Memory Resident:

Yes

Initial Samples Received Date:

04 Oct 2010

Arrival Details

This spyware may be downloaded from the following remote sites:

  • http://{BLOCKED}c3.org/arhiv/install/sea/system.exe

Installation

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

  • %System%\sdra64.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 drops the following non-malicious files:

  • %System%\lowsec\local.ds - copy of the encrypted downloaded file
  • %System%\lowsec\user.ds - used to save the gathered information

(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 creates the following folders:

  • %System%\lowsec

(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 mutexes to ensure that only one of its copies runs at any one time:

  • _AVIRA_2109

It injects itself into the following processes as part of its memory residency routine:

  • SVCHOST.EXE
  • WINLOGON.EXE

Autostart Technique

This spyware modifies the following registry entry(ies) to enable its automatic execution at every system startup:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Winlogon
Userinit = "%System%\userinit.exe, %System%\sdra64.exe,"

(Note: The default value data of the said registry entry is "%System%\userinit.exe,".)

Other System Modifications

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

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Network
UID = "{Computer name}_{Random numbers}"

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

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile
EnableFirewall = 0

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}c3.org/arhiv/install/sea/config.bin1
  • http://{BLOCKED}p-good.org/arhiv/test/alkincc3/cfg1.bin

It attempts to access a website to download a file which contains information where the Trojan can download an updated copy of itself, and where to send its stolen data. This configuration file also contains the following list of targeted bank-related websites from which it steals information:

  • *esube.ingbank.com.tr*intbank*
  • *acikdeniz.denizbank.com*Retail.aspx*
  • *esube.bankasya.com.tr/BenimAsyamWeb/Login.jsf
  • *ziraatbank.com.tr/veribranchZB/inquiry/account_inquiry.jsp*
  • https://www.isbank.com.tr/Internet/ControlLoader.aspx*
  • *acikdeniz.denizbank.com/EBranchForms/Account/Detail/AccountsMain.aspx*
  • *esube.ingbank.com.tr/turkce/giris*
  • *esube.ingbank.com.tr/turkce/Hpl*

It attempts to steal information from the following banks and/or other financial institutions:

  • IS Bank
  • Xiraat Bank
  • Ingbank
  • Deniz Bank
  • Bank Asya

Attacked Entities

This spyware attempts to get information from a list of banks or financial institutions.

Stolen Information

This spyware saves the stolen information in the following file:

  • %System%\lowsec\user.ds

(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 sends the gathered information via HTTP POST to the following URL:

  • http://{BLOCKED}3.org/arhiv/install/db1.php

Other Details

This spyware checks for the presence of the following processes which are related to Outpost Personal Firewall and ZoneLabs Firewall Client:

  • outpost.exe
  • zlclient.exe

It terminates if either of the said processes exist. This is to ensure that it runs uninterrupted. It also has rootkit capabilities, which enables it to hide its processes and files from the user.

Variant Information

This spyware has the following MD5 hashes:

  • 817be05d4d73edb0afc8046fe4cd2935

It has the following SHA1 hashes:

  • 69113d7e774e6b59c95b2e1d31f472a15c89acc2

  SOLUTION

Minimum Scan Engine:

8.900

VSAPI PATTERN File:

7.512.07

VSAPI PATTERN Date:

04 Oct 2010

VSAPI PATTERN Date:

10/4/2010 12:00:00 AM

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 delete files detected as TSPY_ZBOT.YUT using the Recovery Console

[ Learn More ]

Step 3

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_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon
    • From: Userinit = %System%\userinit.exe, %System%\sdra64.exe,
      To: Userinit = %System%\userinit.exe,

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_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Network
    • UID = {Computer name}_{Random numbers}
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\ Services\SharedAccess\Parameters\ FirewallPolicy\StandardProfile
    • EnableFirewall = 0

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.
  • %System%\lowsec

Step 6

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