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TSPY_ZBOT.XXT
Aliases: W32/Zbot.AZD (F-Prot); PWS:Win32/Zbot (Microsoft) ; Troj/Zbot-AGE (Sophos)
Malware type: Spyware
Destructive: No
Platform: Windows 2000, Windows XP, Windows Server 2003
Encrypted: Yes
In the wild: Yes

Overview


This spyware makes use of bogus emails purportedly from Facebook stating that the user's machine is sending spam messages and advises to run the attached tool to prevent the spamming.

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

This spyware inserts JavaScript (JS) code in the Web pages to retrieve user names, passwords, and security codes used in a two-factor authentication in order to transact from within the website.

This spyware arrives as an attachment to email messages spammed by other malware/grayware or malicious users. It 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 attempts to steal information, such as user names and passwords, used when logging into certain banking or finance-related websites.

Technical Details


File size: 138,550 bytes
File type: PE
Memory resident: Yes
Initial samples received date: 30 Nov 2010
Payload: Bypasses Windows Firewall

Arrival Details

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

It 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%\{random1}\{random}.exe - copy of itself
  • %Application Data%\{random2}\{random} - contains encrypted 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 injects itself into the following processes running in the affected system's memory:

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

It creates the following folders:

  • %Application Data%\{random1}
  • %Application Data%\{random2}

(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 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 of mount point of %Windows%} = %Application Data%\{random1}\{random}.exe

Other System Modifications

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

HKEY_CURRENT_USER\Software\Microsoft\
{random}

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

Information Theft

This spyware 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 the following strings in the address bar or title bar:

  • http*chase.com/js_tmp/*
  • http://armskeyboard.com/java/
  • http*bankofamerica.com/js_tmp/*
  • http://armskeyboard.com/java/
  • http*wellsfargo.com/js_tmp/*
  • http://armskeyboard.com/java/
  • https://sitekey.bankofamerica.com/sas/sas-docs/js/verifyImage.js
  • https://sitekey.bankofamerica.com/sas/*
  • http*chase.com*
  • https://onlineeast#.bankofamerica.com/cgi-bin/ias/*/GotoWelcome
  • https://onlineeast#.bankofamerica.com/cgi-bin/ias/*/GotoCustomerServiceMenu
  • https://onlineeast#.bankofamerica.com/cgi-bin/ias/*/GotoWelcome
  • https://sitekey.bankofamerica.com/sas/sas-docs/js/commonscript.js
  • https://sitekey.bankofamerica.com/sas/maint.do
  • https://onlineeast#.bankofamerica.com/cgi-bin/ias/*/CustomerServiceMenuEntryPoint?custAction=75
  • https://*ameritrade.com*
  • *wescom.org*
  • http*countrywide.com*
  • http*suntrust.com*
  • *scottrade.com*
  • *navyfcu.org*
  • https://online.citibank.com/US/JPS/portal/Home.do
  • https://www#.citizensbankonline.com/*/index-wait.jsp
  • https://onlinebanking.nationalcity.com/OLB/secure/AccountList.aspx
  • https://www.53.com/servlet/efsonline/index.html*
  • https://*hb.growfinancial.org*
  • http*chase.com/js_tmp/*
  • http://armskeyboard.com/java/
  • http*bankofamerica.com/js_tmp/*
  • http://armskeyboard.com/java/
  • http*wellsfargo.com/js_tmp/*
  • http://armskeyboard.com/java/
  • https://sitekey.bankofamerica.com/sas/sas-docs/js/verifyImage.js
  • https://sitekey.bankofamerica.com/sas/*
  • http*chase.com*
  • https://onlineeast#.bankofamerica.com/cgi-bin/ias/*/GotoWelcome
  • https://onlineeast#.bankofamerica.com/cgi-bin/ias/*/GotoCustomerServiceMenu
  • https://onlineeast#.bankofamerica.com/cgi-bin/ias/*/GotoWelcome
  • https://sitekey.bankofamerica.com/sas/sas-docs/js/commonscript.js
  • https://sitekey.bankofamerica.com/sas/maint.do
  • https://onlineeast#.bankofamerica.com/cgi-bin/ias/*/CustomerServiceMenuEntryPoint?custAction=75
  • https://*ameritrade.com*
  • *wescom.org*
  • http*countrywide.com*
  • http*suntrust.com*
  • *scottrade.com*
  • *navyfcu.org*
  • https://online.citibank.com/US/JPS/portal/Home.do
  • https://www#.citizensbankonline.com/*/index-wait.jsp
  • https://onlinebanking.nationalcity.com/OLB/secure/AccountList.aspx
  • https://www.53.com/servlet/efsonline/index.html*
  • https://*hb.growfinancial.org*

It accesses the following site to download its configuration file:

  • http://{BLOCKED}ngmad.com/images/smilies/joke.gif

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

  • Ameritrade
  • Bank of America
  • Chase
  • Citibank
  • Citizens
  • Fifth Third
  • Myspace
  • National City
  • Navy Federal Credit Union
  • Scottrade
  • Suntrust
  • Wells Fargo
  • Wescom Credit Union

Stolen Information

This spyware sends the gathered information via HTTP POST to the following URL:

  • http://www.{BLOCKED}al.com/coolstar/coolstar.php

Variant Information

This spyware has the following MD5 hashes:

  • 69af20dbad4d042b1f682abdec824374

It has the following SHA1 hashes:

  • 5895a5247d69d27c814c71d10f8e24307896e3c5

NOTES:

Other Details

Based on analysis of the codes, it has the following capabilities:

  • Inserts JavaScript (JS) code in the Web pages to retrieve user names, passwords, and security codes used in a two-factor authentication in order to transact from within the website.

Solution


Minimum scan engine: 8.900
First VSAPI Pattern File: 7.662.14
First VSAPI Pattern Release Date: 30 Nov 2010
VSAPI OPR Pattern Version: 7.671.00
VSAPI OPR Pattern Release Date: 03 Dec 2010

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

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

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 of mount point of %Windows%} = %Application Data%\{random1}\{malware filename}.exe1
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\AuthorizedApplications\List
    • %WINDOWS%\EXPLORER.EXE = %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.


  • In HKEY_CURRENT_USER\Software\Microsoft\
    • {random}

Step 6

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%\{random1} 
  • %Application Data%\{random2} 
  • In the Look In drop-down list, select My Computer, then press Enter.
  • Once located, select the folder then press SHIFT+DELETE to permanently delete the folder.
  • Repeat the said steps for all folders listed.
  • Step 7

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