TSPY_ZBOT.ZYC

 Analysis by: Karl Dominguez

 ALIASES:

Microsoft: PWS:Win32/Zbot.gen!Y; Sophos: Mal/FakeAV-DV; Kaspersky: Packed.Win32.Krap.hm

 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 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:

154,112 bytes

File Type:

PE

Memory Resident:

Yes

Initial Samples Received Date:

02 Dec 2010

Payload:

Drops files, Downloads files

Infection Points

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

  • http://{BLOCKED}sein.net/22oct_ic3.exe

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
{GUID of mount point of %Windows%} = %Application Data%\{random1}\{malware filename}.exe

Other System Modifications

This spyware adds the following registry keys:

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 accesses the following site to download its configuration file:

  • http://{BLOCKED}adus.cc/22oct_ic3.cpm

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:

  • *.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 information from the following banks and/or other financial institutions:

  • Abbey National
  • Alliance & Leicester
  • Barclays
  • HSBC
  • Natwest

Stolen Information

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

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

  • c64441dad0615ced9aad8c1d5928f073

It has the following SHA1 hashes:

  • d7c3f225746d025bed4ac0cbba8520f8f26d3472

  SOLUTION

Minimum Scan Engine:

8.900

VSAPI PATTERN File:

not yet patched

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 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 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\SYSTEM\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\AuthorizedApplications\List
    • %Windows%\explorer.exe = %Windows%\explorer.exe:*:Enabled:Windows Explorer
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • {GUID of mount point of %Windows%} = %Application Data%\{random1}\{malware filename}.exe

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.ZYC. 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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