Trojan.VBS.GULOADER.A

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 does not have any backdoor routine.

However, as of this writing, the said sites are inaccessible.

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 adds the following processes:

• %System%\WindowsPowerShell\v1.0\powershell.exe "{Shellcode}" → If running on a 32-bit machine
• %Windows%\SysWOW64\WindowsPowerShell\v1.0\powershell.exe "{Malware Path}\{Malware File Name}" - If running on a 64-bit machine
  
  • Executes the following process afterwards:
  • %Windows%\SysWOW64\WindowsPowerShell\v1.0\powershell.exe "{Shellcode}"

(Note: %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.. %Windows% is the Windows folder, where it usually is C:\Windows on all Windows operating system versions.)

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://{BLOCKED}d.com/Udlydsk.jpb

It saves the files it downloads using the following names:

• %Application Data%\Underbore.Gen

(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Roaming on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)

Other Details

This Trojan does the following:

• It checks if the downloaded file exists in the correct path, otherwise connect to the URL every 5 seconds.

However, as of this writing, the said sites are inaccessible.

It does not exploit any vulnerability.