Analysis by: Jed Valderama
ALIASES:

Exploit:SWF/CVE-2012-1535.A (Microsoft)

 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

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

  • 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: Varies
File Type: DOC
Memory Resident: Yes
Initial Samples Received Date: 02 Jun 2011

Arrival Details

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

Installation

This Trojan drops the following files:

  • %User Temp%\Word8.0\ShockwaveFlashObjects.exd
  • %User Temp%\S - detected as BKDR_SIMBOT.SMAZ

(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 creates the following folders:

  • %User Temp%\Word8.0

(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 adds the following registry keys:

HKEY_CLASSES_ROOT\TypeLib\{04B5B5DD-B91F-4F81-B3E5-C548C1B4BD67}

HKEY_CLASSES_ROOT\TypeLib\{04B5B5DD-B91F-4F81-B3E5-C548C1B4BD67}\
1.0\0\win32
Default = "%User Temp%\Word8.0\ShockwaveFlashObjects.exd"

Dropping Routine

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

  SOLUTION

Minimum Scan Engine: 9.200
FIRST VSAPI PATTERN FILE: 8.199.00
FIRST VSAPI PATTERN DATE: 02 Jun 2011

Step 1

For Windows XP and Windows Server 2003 users, before doing any scans, please make sure you disable System Restore to allow full scanning of your computer.

Step 2

Remove malware/grayware files dropped/downloaded by TROJ_MDROPP.ZZXX

    • BKDR_SIMBOT.SMAZ

Step 3

Scan your computer with your Trend Micro product and note files detected as TROJ_MDROPP.ZZXX

Step 4

Delete this registry key

[ Learn More ]

Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.

  • In HKEY_CLASSES_ROOT\TypeLib
    • {04B5B5DD-B91F-4F81-B3E5-C548C1B4BD67}

Step 5

Search and delete the file detected as TROJ_MDROPP.ZZXX

*Note: Some component files may be 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.

To manually delete a malware/grayware file from the affected system:

  1. Right-click Start then click Search....
  2. In the Named input box, type the name of the file that was detected earlier.
  3. In the Look In drop-down list, select My Computer then press Enter.
  4. Once located, select the file then press SHIFT+DELETE to delete it.

Step 6

Search and delete these folders

[ Learn More ]
Please make sure you check the Search Hidden Files and Folders checkbox in the "More advanced options" option to include all hidden folders in the search result.
  • %User Temp%\Word8.0

Step 7

Scan your computer with your Trend Micro product to delete files detected as TROJ_MDROPP.ZZXX. 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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