TSPY_ZBOT.ZWC

 Analysis by: Michael Cabel

 ALIASES:

Microsoft: PWS:Win32/Zbot.gen!Y; Mcafee : W32/Ramnit.a.dr

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

It creates folders where it drops its files.

It modifies the Internet Explorer Zone Settings.

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. 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:

152,576 bytes

File Type:

PE

Memory Resident:

Yes

Initial Samples Received Date:

01 Dec 2010

Arrival Details

This spyware may be dropped by other malware.

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

It may be downloaded from the following remote sites:

  • http://{BLOCKED}sein.net/22oct_pac.exe

Installation

This spyware drops the following files:

  • %Application Data%\{random1}\{random}.exe - copy of itself
  • %Application Data%\{random2}\{random}.{3 random alpha character extension name} - 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 is injected into the following processes running in memory:

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

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} = {malware path and file name}

Other System Modifications

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

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Privacy
CleanCookies = 0

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile\AuthorizedApplications\
List
%Windows%\EXPLORER.EXE = %Windows%\EXPLORER.EXE:*:Enabled:Windows Explorer

Web Browser Home Page and Search Page Modification

This spyware modifies the Internet Explorer Zone Settings.

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:

  • *.barclays.co.uk*bg.php*
  • http://www.barclayscouk.cc/barc/bg.php
  • *.barclays.co.uk*barcaz.php*
  • http://www.barclayscouk.cc/js/barcaz.js
  • *nwolb.co*bg.php*
  • http://www.nwolb.co.uk.servat.cc/natwest/bg.php
  • *nwolb.co*az.php*
  • http://www.nwolb.co.uk.servat.cc/js/natwestaz.js
  • *hsbc.co.uk*bg.php*
  • http://www.nsvc.cc/hsbc/bg.php
  • *hsbc.co.uk*az.php*
  • http://www.nsvc.cc/az.js
  • *alliance*leicester.co.uk*bg.php*
  • http://www.mybank.alliance-leiceter.cc/leicester/bg.php
  • *alliance*leicester.co.uk*leicesteraz.php*
  • http://www.mybank.alliance-leiceter.cc/js/leicesteraz.js
  • *firstdirect.com*bg.php*
  • http://www1.banking.firstdirest.cc/first/bg.php
  • *firstdirect.com*firstaz.php*
  • http://www1.banking.firstdirest.cc/js/firstaz.js
  • *abbeynational.co.uk*abbeyaz.*php*
  • http://myonlineaccounts2.abbeynational.servat.cc/js/abbeyaz.js
  • *abbeynational.co.uk*bg.php*
  • http://myonlineaccounts2.abbeynational.servat.cc/abbey/bg.php
  • *retail.abbeynational.co.uk/EBAN_ENS/BtoChannelDriver.ssobto*
  • *.abbeynational.co.uk/*
  • *.barclays.co.uk*
  • *nwolb.co*
  • *.mybank.alliance-leicester.co.uk*
  • *.firstdirect.com*splash*trusteer*
  • *.firstdirect.com/1/2/*
  • *.hsbc.co.uk/1*

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.

It accesses the following site to download its configuration file:

  • http://{BLOCKED}sein.net/22oct_pac.cpm
  • http://{BLOCKED}otions.ru/14oct_usa.cpm
  • http://{BLOCKED}icks.ru/14oct_usa.cpm

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

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

  • Alliance & Leicester
  • Barclays
  • HSBC
  • Natwest
  • Abbeynational

Drop Points

Stolen information is uploaded to the following websites:

  • http://{BLOCKED}cyis.com/yahooman.php

Variant Information

This spyware has the following MD5 hashes:

  • fd41bdfe93a63542169995112c464785

It has the following SHA1 hashes:

  • 365ae5f6c867838322c0da44f86f610694806dc3

  SOLUTION

Minimum Scan Engine:

8.900

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.ZWC

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\Internet Explorer\Privacy
    • CleanCookies = 0
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • {GUID} = {malware path and file name}
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\AuthorizedApplications\List
    • %Windows%\EXPLORER.EXE = %Windows%\EXPLORER.EXE:*:Enabled:Windows Explorer

Step 5

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

Step 6

Reset Internet security settings

[ Learn More ]

Step 7

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