Analysis by: Mark Joseph Manahan

ALIASES:

Troj/SWFExp-CH (Sophos) ,Trojan horse Exploit_c.YZX (AVG) ,Exploit.Win32.CVE-2013 (Ikarus) ,HEUR:Exploit.SWF.CVE-2013-5331.a (Kaspersky) ,Exploit:Win32/CVE-2013-5331 (Microsoft) ,SWF/Exploit.CVE-2013-5331.A trojan (Eset) ,Trojan.Mdropper (Symantec)

 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.

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

  TECHNICAL DETAILS

File Size: 32,768 bytes
File Type: DOC, SWF
Memory Resident: No
Initial Samples Received Date: 14 Jan 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.

Other Details

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

  • Execute a malicious code from http://{BLOCKED}.{BLOCKED}.111.219/ipaddrs/shell

It is a zero-day exploit for the following vulnerability:

  SOLUTION

Minimum Scan Engine: 9.700
FIRST VSAPI PATTERN FILE: 10.540.07
FIRST VSAPI PATTERN DATE: 14 Jan 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

Scan your computer with your Trend Micro product to delete files detected as TROJ_SHELLCOD.A. 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 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.


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