TSPY_ZBOT.YUYASU

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 Internet Explorer security settings. This puts the affected computer at greater risk, as it allows malicious URLs to be accessed by the computer.

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

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.

Installation

This spyware drops the following files:

• %User Temp%\{random file name 4}.bat - deletes initially executed copy of malware
• %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: %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.. %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 copies of itself into the affected system:

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

(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 creates the following folders:

• %Application Data%\{random folder name 3}
• %Application Data%\{random folder name 1}
• %Application Data%\{random folder name 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 attaches itself to all running processes.

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 name 1}\{random file name 1}.exe"

Other System Modifications

This spyware adds the following registry entries:

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

Web Browser Home Page and Search Page Modification

This spyware modifies Internet Explorer zone settings.

Information Theft

This spyware accesses the following site to download its configuration file:

• www.{BLOCKED}rolc.com/file.php|file=config.dll

It steals the following information:

• FTP credentials
• Internet session cookies
• Flash player data
• Personal certificates
• Video capture
• Keyboard logs
• Clipboard logs

Other Details

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

• http://www.google.com/webhp

It deletes the initially executed copy of itself

NOTES:

It queries for the following registry keys to check for the installed security related software:

If found, it avoids injecting on the following processes on the system:

It steals passwords and usernames from cache and cookies of the following browsers: