TROJ_ARTIEF.NSA

April 07, 2014
 Analysis by: Alvin John Nieto
 ALIASES:

Exploit:Win32/CVE-2012-2539 (Microsoft), Win32/Exploit.CVE-2014-1761.C trojan (ESET), HEUR:Exploit.MSWord.CVE-2014-1761.gen (Kaspersky), Exploit-CVE2014-1761 (McAfee)

 PLATFORM:

Windows 2000, Windows Server 2003, Windows XP (32-bit, 64-bit), Windows Vista (32-bit, 64-bit), Windows 7 (32-bit, 64-bit)

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Downloaded from the Internet, Dropped by other malware

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.

  TECHNICAL DETAILS

File Size:

790,048 bytes

Memory Resident:

Yes

Initial Samples Received Date:

03 Apr 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.

Installation

This Trojan drops and executes the following files:

  • %User Temp%\..\svchost.exe - detected as TROJ_CYCOOMER.A

(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.)

Other System Modifications

This Trojan deletes the following registry keys:

HKEY_CURRENT_USER\Software\Microsoft\
Office\14.0\Word\
Resiliency

HKEY_CURRENT_USER\Software\Microsoft\
Office\12.0\Word\
Resiliency

Other Details

This Trojan is a zero-day exploit for the following vulnerability:

  • CVE-2014-1761

For workarounds on the aforementioned vulnerability, please see the following page:

  • https://support.microsoft.com/kb/2953095

NOTES:

This Trojan checks the following file for system updates installed later than April 08, 2014. If it finds an update with the aforementioned date, it terminates its process:

  • C:\Windows\SoftwareDistribution\ReportingEvents.log

  SOLUTION

Minimum Scan Engine:

9.700

FIRST VSAPI PATTERN FILE:

10.704.02

FIRST VSAPI PATTERN DATE:

03 Apr 2014

VSAPI OPR PATTERN File:

10.705.00

VSAPI OPR PATTERN Date:

03 Apr 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

Remove the malware/grayware file that dropped/downloaded TROJ_ARTIEF.NSA

    TROJ_CYCOOMER.A

Step 3

Restore these deleted registry keys/values from backup

*Note: Only Microsoft-related keys/values will be restored. If the malware/grayware also deleted registry keys/values related to programs that are not from Microsoft, please reinstall those programs on your computer.

  • HKEY_CURRENT_USER\Software\Microsoft\Office\14.0\Word\Resiliency
  • HKEY_CURRENT_USER\Software\Microsoft\Office\12.0\Word\Resiliency

Step 4

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

https://support.microsoft.com/kb/2953095

Step 5

Scan your computer with your Trend Micro product to delete files detected as TROJ_ARTIEF.NSA. 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.


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