TSPY_ZBOT.NBY

March 14, 2013

Analysis by: Adrianne Chester Camat

ALIASES:

PWS:Win32/Zbot(Microsoft)

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

It deletes itself after execution.

TECHNICAL DETAILS

File Size:

336,384 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

06 Mar 2013

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 1}\{random}.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 1}\{random}.{random}
%Application Data%\{random folder 2}\{random}.{random}
%Application Data%\Microsoft\Address Book\{user name}.wab
%Application Data%\Microsoft\Address Book\{user name}.wab~

It creates the following folders:

%Application Data%\{random folder 1}
%Application Data%\{random folder 2}
%Application Data%\Microsoft\Address Book

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

Other System Modifications

This spyware adds the following registry keys:

HKEY_CURRENT_USER\Software\Microsoft\
{random}

HKEY_CURRENT_USER\Software\Microsoft\
WAB

HKEY_CURRENT_USER\Software\Microsoft\
WAB\WAB4

HKEY_CURRENT_USER\Software\Microsoft\
WAB\WAB4\Wab File Name

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Privacy

It adds the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
{random}
{random} = {random value}

HKEY_CURRENT_USER\Software\Microsoft\
WAB\WAB4
OlkContactRefresh = 0

HKEY_CURRENT_USER\Software\Microsoft\
WAB\WAB4
OlkFolderRefresh = 0

HKEY_CURRENT_USER\Software\Microsoft\
WAB\WAB4
FirstRun = 1

HKEY_CURRENT_USER\Software\Microsoft\
WAB\WAB4\Wab File Name
(Default) = "%Application Data%\Microsoft\Address Book\{user name}.wab"

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

It modifies the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings\
Zones\0
1609 = 0