Analysis by: Sabrina Lei Sioting
 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

This Trojan contains an embedded malicious .SWF file that it uses to successfully exploit the specific vulnerability. The malicious .SWF file is detected by Trend Micro as SWF_EXPLOIT.WMP.

It executes the dropped and embedded files. As a result, routines of these malware are exhibited on the infected system.

This Trojan arrives as attachment to mass-mailed email messages.

It takes advantage of software vulnerabilities in certain software to drop malicious files.

Once a malware successfully exploits the said vulnerability, it causes certain actions to be done on the system.

  TECHNICAL DETAILS

File Size: Varies
File Type: DOC
Memory Resident: No
Initial Samples Received Date: 15 Apr 2011

Arrival Details

This Trojan arrives as attachment to mass-mailed email messages.

Dropping Routine

This Trojan takes advantage of unknown vulnerabilities in the following software to drop malicious files:

  • Unspecified vulnerability in Adobe Flash Player

Other Details

Once a malware successfully exploits the said vulnerability, it causes the following actions to be done on the system:

    NOTES:

    • Drops the following file on the infected system:
      • %User Temp%\scvhost.exe
    • It executes the dropped and embedded files. As a result, routines of these malware are exhibited on the infected system.
    • It also attempts to hide its malicious routines from the user by dropping and opening the non-malicious .DOC file, %User Temp%\AAAA.It deletes and replaces itself with the said .DOC file after executing.

    This Trojan contains an embedded malicious .SWF file that it uses to successfully exploit the aforementioned vulnerability. The malicious .SWF file is detected by Trend Micro as SWF_EXPLOIT.WMP.

    It executes the dropped and embedded files. As a result, routines of these malware are exhibited on the infected system.

      SOLUTION

    Minimum Scan Engine: 8.900
    FIRST VSAPI PATTERN FILE: 7.978.11
    FIRST VSAPI PATTERN DATE: 15 Apr 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_MDROP.SMJ

    Step 3

    Search and delete these files

    [ Learn More ]
    There may be some component 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%\AAAA
    • %User Temp%\scvhost.exe

    Step 4

    Scan your computer with your Trend Micro product to delete files detected as TROJ_MDROP.SMJ. 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.

    NOTES:

    For updates on available workarounds and patches for this vulnerability, please refer to the following page:


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