Analysis by: RonJay Kristoffer Caragay
ALIASES:

Exploit:VBS/CVE-2014-6332 (Microsoft); Exploit.VBS.CVE-2014-6332 (Ikarus); BS/YeaGun!exploit.CVE20146332 (Fortinet)

 PLATFORM:

Windows

 OVERALL RISK RATING:
 DAMAGE POTENTIAL:
 DISTRIBUTION POTENTIAL:
 REPORTED INFECTION:
 INFORMATION EXPOSURE:

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

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 may be hosted on a website and run when a user accesses the said website.

  TECHNICAL DETAILS

File Size: 6,594 bytes
File Type: VBS
Memory Resident: No
Initial Samples Received Date: 16 Dec 2014

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.

It may be hosted on a website and run when a user accesses the said website.

Dropping Routine

This Trojan drops the following files:

  • %User Temp%\1.vbs
  • %User Profile%\appdata\locallow\123456.txt
  • %Temp%\temp.exe

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

It takes advantage of the following software vulnerabilities to drop malicious files:

Other Details

This Trojan connects to the following possibly malicious URL:

  • http://{BLOCKED}.{BLOCKED}.179.191/ok.jpg

  SOLUTION

Minimum Scan Engine: 9.700
FIRST VSAPI PATTERN FILE: 11.348.03
FIRST VSAPI PATTERN DATE: 16 Dec 2014
VSAPI OPR PATTERN File: 11.349.00
VSAPI OPR PATTERN Date: 16 Dec 2014

Step 1

Before doing any scans, Windows XP, Windows Vista, and Windows 7 users must disable System Restore to allow full scanning of their computers.

Step 2

Note that not all files, folders, and registry keys and entries are installed on your computer during this malware's/spyware's/grayware's execution. This may be due to incomplete installation or other operating system conditions. If you do not find the same files/folders/registry information, please proceed to the next step.

Step 3

Close all opened browser windows

Step 4

Search and delete this file

[ Learn More ]
There may be some files that are hidden. Please make sure you check the Search Hidden Files and Folders checkbox in the "More advanced options" option to include all hidden files and folders in the search result.  
  • %User Temp%\1.vbs
  • %User Profile%\appdata\locallow\123456.txt
  • %Temp%\temp.exe

Step 5

Scan your computer with your Trend Micro product to delete files detected as VBS_EXPLOIT.THG. If the detected files have already been cleaned, deleted, or quarantined by your Trend Micro product, no further step is required. You may opt to simply delete the quarantined files. Please check this Knowledge Base page for more information.

Step 6

Download and apply these security patches Refrain from using these products until the appropriate patches have been installed. Trend Micro advises users to download critical patches upon release by vendors.


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