ALIASES:

Downloader(Symantec), Exp/WMF-A(Sophos), Exploit.Win32.IMG-WMF(Kaspersky), EXP/MS06-001.WMF(Avira), CVE-2005-4560 (not disinfectable)(F-Prot), Exploit-WMF(McAfee)

 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 is the Trend Micro detection for a modified Windows Metafile (.WMF) that takes advantage of certain Windows vulnerabilities.

It may also take advantage of an unpatched Windows Graphics Rendering Engine (GRE) vulnerability. This zero-day exploit causes certain functions of Windows GRE to perform an unauthorized memory access when rendering the WMF file. Users viewing the said file are bound to experience a denial of service attack causing Windows Explorer to crash and restart.

  TECHNICAL DETAILS

File Size: Varies
File Type: WMF
Memory Resident: Yes
Initial Samples Received Date: 09 Dec 2005
Payload: Crash affected image viewer programs and/or Windows Explorer, Downloads files, Executes arbitrary codes or other programs

NOTES:

This is the Trend Micro detection for a modified Windows Metafile (.WMF) that takes advantage of the following Windows vulnerabilities:

It may also take advantage of an unpatched Windows Graphics Rendering Engine (GRE) vulnerability. This zero-day exploit causes certain functions of Windows GRE to perform an unauthorized memory access when rendering the WMF file. Users viewing the said file are bound to experience a denial of service attack causing Windows Explorer to crash and restart.

Once any of the vulnerabilities are exploited successfully, the malicious .WMF file may perform any of the following actions:

  • Crash affected image viewer programs and/or Windows Explorer
  • Download other malicious files
  • Execute arbitrary codes or other programs

  SOLUTION

Minimum Scan Engine: 7.000
FIRST VSAPI PATTERN FILE: 4.356.01
FIRST VSAPI PATTERN DATE: 21 Mar 2007
VSAPI OPR PATTERN File: 8.793.00
VSAPI OPR PATTERN Date: 21 Feb 2012

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

Scan your computer with your Trend Micro product to delete files detected as EXPL_WMF.GEN. 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 3

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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