TSPY_ZBOT.EMA

 Analysis by: Anthony Joe Melgarejo

 ALIASES:

PWS:Win32/Zbot (Microsoft), TR/PSW.Zbot.JC.1 (Antivir), W32/Luder.AYZB!tr (Fortinet), Win32/Spy.Zbot.AAU trojan (ESET)

 PLATFORM:

Windows 2000, Windows Server 2003, Windows XP (32-bit, 64-bit), Windows Vista (32-bit, 64-bit), Windows 7 (32-bit, 64-bit)

 OVERALL RISK RATING:
 REPORTED INFECTION:
 SYSTEM IMPACT RATING:
 INFORMATION EXPOSURE:

  • Threat Type: Spyware

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

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

It modifies the Internet Explorer Zone Settings.

It deletes the initially executed copy of itself.

  TECHNICAL DETAILS

File Size:

1,016,583 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

30 May 2013

Arrival Details

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

Installation

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

  • %Application Data%\{random folder}\{random file name}.exe

(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 drops the following files:

  • %Application Data%\{random folder 2}\{random file name 2}.{random extension}

(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 creates the following folders:

  • %Application Data%\{random folder 1}
  • %Application Data%\{random folder 2}

(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.)

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} = "%Application Data%\{random folder 1}\{random file name 1}.exe"

Other System Modifications

This spyware adds the following registry keys:

HKEY_CURRENT_USER\Software\Microsoft\
{random letters}

HKEY_CURRENT_USER\Software\Microsoft\
WAB

It adds the following registry entries:

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

Web Browser Home Page and Search Page Modification

This spyware modifies the Internet Explorer Zone Settings.

Other Details

This spyware connects to the following possibly malicious URL:

  • http://www.{BLOCKED}ytree.co.za/images/tm/config.bin
  • http://www.{BLOCKED}ytree.co.za/images/tm/gate.php

It deletes the initially executed copy of itself