TSPY_ZBOT.SMAA3

This malware is involved in a malicious spam campaign that took place on December 2013. It serves as the final payload downloaded by the malicious spam's attachment. Users affected by this malware may find critical user information stolen from their systems, and their online banking accounts compromised.

To get a one-glance comprehensive view of the behavior of this Spyware, refer to the Threat Diagram shown below.

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 may be downloaded from remote sites by other malware.

It is injected into all running processes to remain memory resident.

It modifies the Internet Explorer Zone Settings.

It deletes the initially executed copy of itself.

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.

It may be downloaded from remote site(s) by the following malware:

• TROJ_UPATRE.GY

It may be downloaded from the following remote sites:

• http://{BLOCKED}ame.com/wp-content/uploads/2009/06/pdf.enc
• http://{BLOCKED}rnia89.com/wp-content/uploads/2013/05/pdf.enc

Installation

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

• %Application Data%\{random1}\{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%\{random2}\{random}.{random}
• %Application Data%\Microsoft\Address Book\{OS version}.wab

(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%\{random1}
• %Application Data%\{random2}
• %Application Data%\Microsoft\Address Book

(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 all running processes to remain memory resident.

It adds the following mutexes to ensure that only one of its copies runs at any one time:

• Global\{GUID}
• Local\{GUID}

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%\{random1}\{random}.exe"

Other System Modifications

This spyware adds the following registry keys:

HKEY_CURRENT_USER\Software\Microsoft\
{random}

HKEY_CURRENT_USER\Software\Microsoft\
WAB

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"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile\GloballyOpenPorts\
List
{port}:UDP = "{port}:UDP:Enabled:UDP {port}"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile\GloballyOpenPorts\
List
{port}:TCP = "{port}:TCP:Enabled:TCP {port}"

Web Browser Home Page and Search Page Modification

This spyware modifies the Internet Explorer Zone Settings.

Other Details

This spyware connects to the following URL(s) to check for an Internet connection:

• http://www.bing.com/
• http://www.google.com/

It deletes the initially executed copy of itself

NOTES:

The configuration file may contain URLs where it downloads an updated copy of itself and sends its gathered information. It may also contain URLs of its target online banking and finance-related sites from where it steals information.

It may also gather the following information from the affected system:

• Data on Cookie files (URLs)
• Email-related information such as account names, email addresses, passwords, server data, and server port
• Email information stored in the user’s Windows Address Book (WAB) file

It connects to random generated IP addresses.

It sends out DNS queries to a randomized domain name with the following extensions:

• .info
• .com
• .biz
• .org
• .net
• .ru

It connects to randomized domain name with the following format:

• {pseudorandom characters}.{extension}