Analysis by: Karl Dominguez

ALIASES:

Microsoft : PWS:Win32/Zbot ; Kaspersky : Trojan-Spy.Win32.Zbot

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

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

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: 153,088 bytes
File Type: PE
Memory Resident: Yes
Initial Samples Received Date: 27 Nov 2010
Payload: Drops files, Downloads files

Arrival Details

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

Infection Points

This spyware arrives as a file downloaded from the following URLs:

  • http://{BLOCKED}ost/sp05.bin

Installation

This spyware drops the following files:

  • %Application Data%\{random1}\{random}.exe - copy of itself
  • %Application Data%\{random2}\{random}.{random} - contains encrypted stolen 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 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 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
{random CLSID} = %Application Data%\{random1}\{malware filename}.exe

Other System Modifications

This spyware adds the following registry keys:

HKEY_CURRENT_USER\Software\Microsoft\
{random}

Information Theft

This spyware accesses the following site to download its configuration file:

  • http://{BLOCKED}lfotball.no/images/logo.jpg

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:

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

  • Ameritrade
  • Bank of America
  • Chase
  • Citibank
  • Citizens
  • Fifth Third Bank
  • Grow Online Banking
  • National City
  • Navy Federal Credit Union
  • Scottrade
  • Suntrust
  • Wescom Credit Union

Stolen Information

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

  • http://{BLOCKED}neforyou.com/index.php

Other Details

This spyware does the following:

  • It 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.

Variant Information

This spyware has the following MD5 hashes:

  • 0ad6e24b502f1080d892a7af286b0d5d

It has the following SHA1 hashes:

  • 9d33779b7bf9b58a2d7f4ff7e0d23116fae414eb

  SOLUTION

Minimum Scan Engine: 8.900
VSAPI PATTERN File: 7.654.01
VSAPI PATTERN Date: 27 Nov 2010
VSAPI PATTERN Date: 11/27/2010 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

Restart in Safe Mode

[ Learn More ]

Step 3

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
    • {random CLSID} = %Application Data%\{random1}\{malware filename}.exe

Step 4

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

Step 6

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