VBS_ZERLODAT.B

This Trojan arrives as an attachment to email messages spammed by other malware/grayware or malicious users. It may arrive bundled with malware packages as a malware component.

It does not have any propagation routine.

It does not have any backdoor routine.

As of this writing, the said sites are inaccessible.

It does not have any information-stealing capability.

Arrival Details

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

It may arrive bundled with malware packages as a malware component.

Installation

This Trojan drops the following files:

• %User Temp%\nesgf.dat -> copy of encrypted downloaded file, san0329[1].dat, mentioned on the Download Routine
• %User Temp%\ncags.dat -> decrypted form of “%User Temp%\nesgf.dat”

(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.)

It drops and executes the following files:

• %User Temp%\sangin.exe -> copy of “%User Temp%\ncags.dat” in executable type, modified by the malware by appending/adding “0000000000000000000…” at the end of the file

(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.)

Propagation

This Trojan does not have any propagation routine.

Backdoor Routine

This Trojan does not have any backdoor routine.

Rootkit Capabilities

This Trojan does not have rootkit capabilities.

Download Routine

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

• http://www.{BLOCKED}-bs.com/room/dalianmingzhu/dalianmingzhu-jp.html

It saves the files it downloads using the following names:

• %Temporary Internet Files%\san0329[1].dat -> possibly serves as the initial downloaded file (encrypted), once the download URL was accessed by the malware successfully

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

As of this writing, the said sites are inaccessible.

Information Theft

This Trojan does not have any information-stealing capability.

Other Details

This Trojan does the following:

• After executing the malicious routines, the malware will delete these files:
  • %User Temp%\nesgf.dat
  • %User Temp%\ncags.dat
• After connecting on the download URL, the malware will search for on the directories and subdirectories of %User Profile%\AppData\Local\Microsoft\Windows\* for the file san0329[1].dat (possible downloaded file mentioned above). If found, the malware will drop a copy of san0329[1].dat using the filename %User Temp%\nesgf.dat.
• Upon execution of the malware, it will Sleep for 300,000 milliseconds, in order to have a delay on its behavior/malicious routine.

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