TROJ_BREDOLAB.CJ

This Trojan arrives as an attachment to email messages spammed by other malware/grayware or malicious users. It arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

As of this writing, the said sites are inaccessible.

It deletes the initially executed copy of itself.

Arrival Details

This Trojan arrives as an attachment to email messages spammed by other malware/grayware or malicious users.

It 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 Startup%\{random}32.exe

(Note: %User Startup% is the current user's Startup folder, which is usually C:\Windows\Profiles\{user name}\Start Menu\Programs\Startup on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Start Menu\Programs\Startup on Windows NT, and C:\Documents and Settings\{User name}\Start Menu\Programs\Startup.)

It drops the following non-malicious file:

• %Application Data%\avdrn.dat

(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Windows\Profiles\{user name}\Application Data on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Application Data on Windows NT, and C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000, XP, and Server 2003.)

It injects itself into the following processes running in the affected system's memory:

• Explorer.exe
• Svchost.exe

Download Routine

This Trojan connects to the following website(s) to download and execute a malicious file:

• {BLOCKED}oup128.ru

As of this writing, the said sites are inaccessible.

Other Details

This Trojan deletes the initially executed copy of itself

NOTES:

It has a function that checks for the system conditions to which this malware is running into. Once it identified that it is running in an analysis environment, it terminates the system and causes Blue Screen of Death (BSOD).

The function checks for system files that may only be unique to a virtual machine environment. Vmware files are being checked on this function and other related machine that is emulated. The following are the system files it checks:

• dbghelp.dll
• hgfs.sys
• prleth.sys
• sbiedll.dll
• vmhgfs.sys

It also checks the following machine information:

• GetComputerName
• GetUserName
• ProductID
• System information
• SystemBiosVersion

It gets the hashes of each of the information above and match it against a list of hashes written within the malware body.

It hooks the following API:

• ZwQueryDirectoryFile