TROJ_ARTIEF.YYLD

July 18, 2014
 Analysis by: RonJay Kristoffer Caragay
 ALIASES:

Exploit.MSWord.CVE-2012-0158.ca (Kaspersky), Exploit:Win32/CVE-2012-0158 (Microsoft), Exp/20120158-A (Sophos), Win32/Exploit.CVE-2012-0158.DZ trojan (NOD32)

 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:

  • In the wild: Yes

  OVERVIEW

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

It executes the dropped file(s). As a result, malicious routines of the dropped files are exhibited on the affected system.

  TECHNICAL DETAILS

File Size:

155,757 bytes

File Type:

DOC, RTF

Memory Resident:

No

Initial Samples Received Date:

14 Jul 2014

Arrival Details

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

    Dropping Routine

    This Trojan drops the following files:

    • %User Temp%\conirn.exe
    • %User Temp%\China is busy in American backyard.doc

    (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.)

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

    It executes the dropped file(s). As a result, malicious routines of the dropped files are exhibited on the affected system.

    Other Details

    More information on this vulnerability can be found below:

    NOTES:

    This Trojan opens its dropped non-malicious .DOC file %User Temp%\China is busy in American backyard.doc as a decoy to trick users that they are opening a legitimate document.

      SOLUTION

    Minimum Scan Engine:

    9.700

    FIRST VSAPI PATTERN FILE:

    10.922.04

    FIRST VSAPI PATTERN DATE:

    14 Jul 2014

    VSAPI OPR PATTERN File:

    10.923.00

    VSAPI OPR PATTERN Date:

    14 Jul 2014

    Step 1

    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 2

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

    Step 3

    Search and delete these files

    [ 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%\conirn.exe
    • %User Temp%\China is busy in American backyard.doc

    Step 4

    Scan your computer with your Trend Micro product to delete files detected as TROJ_ARTIEF.YYLD. 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 5

    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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