TROJ_ALUREON.ALW

This Trojan attempts to overwrite the Master Boot Record (MBR) with its codes. However, this may cause problems in the system such as boot failure.

It attempts to perform certain queries on the affected system.

It creates several components in a hidden device, depending on whether the machine is 32 or 64 bit.

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

It does not have any propagation routine.

It also has rootkit capabilities, which enables it to hide its processes and files from the user.

It does not have any information-stealing capability.

It deletes the initially executed copy of itself.

Arrival Details

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

• %User Temp%\Realtek_AC97.exe
• %User Temp%\{random}.exe

(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista and 7.)

Its DLL component is injected to the following process(es):

• svchost.exe

Propagation

This Trojan does not have any propagation routine.

Rootkit Capabilities

This Trojan also has rootkit capabilities, which enables it to hide its processes and files from the user.

Information Theft

This Trojan does not have any information-stealing capability.

Other Details

This Trojan deletes the initially executed copy of itself

NOTES:

It attempts to overwrite the Master Boot Record (MBR) with its codes to automatically execute its components upon system boot.

It attempts to perform the following queries on the affected system:

• SELECT * FROM Win32_BIOS WHERE Manufacturer LIKE "%Xen%"
• SELECT * FROM Win32_BIOS WHERE Manufacturer LIKE "%QEMU%"
• SELECT * FROM Win32_BIOS WHERE Manufacturer LIKE "%Bochs%"
• SELECT * FROM Win32_DiskDrive WHERE Model LIKE "%Xen%"
• SELECT * FROM Win32_DiskDrive WHERE Model LIKE "%QEMU%"
• SELECT * FROM Win32_DiskDrive WHERE Model LIKE "%Bochs%"
• SELECT * FROM Win32_DiskDrive WHERE Model LIKE "%Red Hat%"
• SELECT * FROM Win32_SCSIController WHERE Name LIKE "%Citrix%"
• SELECT * FROM Win32_SCSIController WHERE Manufacturer LIKE "%Xen%"
• SELECT * FROM Win32_SCSIController WHERE Manufacturer LIKE "%Red Hat%"
• SELECT * FROM Win32_Processor WHERE Name LIKE "%QEMU%"
• SELECT * FROM Win32_Process WHERE Name = "CaptureClient.exe"

These queries are used by the malware to identify if it is running under a sandbox or virtual machine.

It creates the following components in a hidden file system, depending on whether the machine is 32 or 64 bit:

• cmd32.dll / cmd64.dll - TROJ_ALUREON.ALW
• dbg32 / dbg64 - TROJ_TDSS.ADH, TROJ_TDSS.BME
• drv32.sys / drv64.sys - TROJ_ALUREON.ALW
• ldr32.exe / ldr64.exe - TROJ_TDSS.BMG, TROJ_TDSS.BMH
• main - configuration file

This malware connects to the following URLs to download additional components:

• http://{BLOCKED}don-{random numbers}.com/cat/v3
• http://{BLOCKED}at-{random numbers}.com/cat/v3
• http://{BLOCKED}en-{random numbers}.com/cat/v3
• http://{BLOCKED}ck-{random numbers}.com/cat/v3
• http://{BLOCKED}ila.com/cat/v3
• http://{BLOCKED}zuck.com/cat/v3
• http://{BLOCKED}etclick.com/cat/v3

Note that the URLs generated may change from time to time.

The malware appends the following to the URLs above:

• /files/mods/cmd32
• /files/mods/bbr232
• /files/mods/serf332

A sample download URL would be:

• http://{BLOCKED}852171.com/cat/v3/files/mods/cmd32

The downloaded files are encrypted. After decryption, the downloaded files bbr232 and serf332 are then injected into any of the following processes:

• iexplore.exe
• explorer.exe
• firefox.exe
• safari.exe
• chrome.exe
• WebKit2WebProce
• WebKit2WebProc

It stores its backup configuration files in images hosted at the following legitimate websites:

• http://{BLOCKED}yq.wordpress.com/
• http://{BLOCKED}aqevi.livejournal.com/
• http://{BLOCKED}vubi.wordpress.com/
• http://{BLOCKED}ejuq.livejournal.com/
• http://{BLOCKED}vesoja.wordpress.com/

The malware downloads the pages of the URLs above and then searches for the following tags:

It then extracts the "jpg" file pointed to by the "img src" tag, and downloads the JPG file. The downloaded JPEGs contain encrypted configuration files which include details about the malware's modules, servers, and backup configuration URLs.

The downloaded files are all stored in its hidden file system.