TSPY_ZBOT.YUYFI

July 21, 2014
 Analysis by: Abraham Latimer Camba
 ALIASES:

Trojan horse Zbot.JPM (AVG), Trojan-Spy.Win32.Zbot.tefa (Kaspersky), PWS:Win32/Zbot (Microsoft), Win32/Spy.Zbot.AAO trojan (ESET), Trojan.Win32.Generic!BT (Sunbelt), TrojanSpy.Zbot (VBA32), TR/Kazy.391055.1 (AntiVir)

 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:
 DAMAGE POTENTIAL:
 DISTRIBUTION POTENTIAL:
 REPORTED INFECTION:
 INFORMATION EXPOSURE:

  • Threat Type: Spyware

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

This spyware arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

It modifies the Internet Explorer Zone Settings.

  TECHNICAL DETAILS

File Size:

336,384 bytes

File Type:

EXE

Initial Samples Received Date:

21 Jun 2014

Arrival Details

This spyware arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

Installation

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

  • %Application Data%\{random folder name 1}\{random file name 1}.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 name 2}\{random file name 2}.{random extension 1}
  • %Application Data%\{random folder name 3}\{random file name 3}.{random extension 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.)

It creates the following folders:

  • %Application Data%\{random folder name 1}
  • %Application Data%\{random folder name 2}
  • %Application Data%\{random folder name 3}

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

Other System Modifications

This spyware adds the following registry keys:

HKEY_CURRENT_USER\Software\Microsoft\
{random key}

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Privacy

It adds the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
{random key}
{random value 2} = "{hex values}"

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.

Other Details

This spyware connects to the following possibly malicious URL:

  • http://{BLOCKED}et.su/CartList.php