TSPY_ZBOT.YUYAXA

This Trojan Spy arrives as an attachment to email messages mass-mailed by other malware/grayware or malicious users.

It does not have any propagation routine.

It does not have any backdoor routine.

It modifies the Internet Explorer Zone Settings.

It steals certain information from the system and/or the user.

It deletes the initially executed copy of itself.

Arrival Details

This Trojan Spy arrives as an attachment to email messages mass-mailed by other malware/grayware or malicious users.

Installation

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

• %Application Data%\{random folder 1}\{random filename 1}.exe - detected as TSPY_ZBOT.YUYAXA

(Note: %Application Data% is the Application Data folder, where it usually is C:\Documents and Settings\{user name}\Application Data on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Roaming on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.)

It drops the following files:

• %Application Data%\{random folder 2}\{random file name 2}.{random extension}
• %Application Data%\{random folder 2}\{random file name 2}.tmp
• %User Temp%\tmp{random characters}.bat

(Note: %Application Data% is the Application Data folder, where it usually is C:\Documents and Settings\{user name}\Application Data on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Roaming on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.. %User Temp% is the user's temporary folder, where it usually is C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local\Temp on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.)

It creates the following folders:

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

(Note: %Application Data% is the Application Data folder, where it usually is C:\Documents and Settings\{user name}\Application Data on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Roaming on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.)

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

• Local\{GUID}
• Global\{GUID}

It injects codes into the following process(es):

• explorer.exe

Autostart Technique

This Trojan Spy 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 filename 1}.exe "

Other System Modifications

This Trojan Spy 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\
Internet Explorer\Privacy
CleanCookies = "0"

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

Propagation

This Trojan Spy does not have any propagation routine.

Backdoor Routine

This Trojan Spy does not have any backdoor routine.

Web Browser Home Page and Search Page Modification

This Trojan Spy modifies the Internet Explorer Zone Settings.

Download Routine

This Trojan Spy connects to the following URL(s) to download its configuration file:

• http://{BLOCKED}solutions.com/web/themes/cer/cfg.bin

Information Theft

This Trojan Spy steals the following information:

• 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
• Online banking credentials
• Personal digital certificate

Other Details

This Trojan Spy deletes the initially executed copy of itself

NOTES:

It does not have rootkit capabilities.

It does not exploit any vulnerability.

The configuration file may contain URLs where it downloads an updated copy of itself and where it sends its gathered information. It may also contain URLs of its target online banking and finance-related sites from where it steals the information. Note that the contents of the file, hence the list of websites to monitor, may change anytime.