TROJ_MDROP.AIK

February 14, 2013
 Analysis by: Michael Cabel
 PLATFORM:

Mac OS X

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Dropped by other malware, Downloaded from the Internet, Spammed via email

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

Varies

File Type:

DOC

Memory Resident:

No

Initial Samples Received Date:

14 Feb 2013

Payload:

Drops files

Arrival Details

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

It arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

Dropping Routine

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

  • Vulnerabilities in certain versions of Microsoft Office Word

Other Details

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

  • Drops the following files:

    /tmp/l - OSX Backdoor
    /tmp/l.doc - Normal document file
    /tmp/l.sh - bash file to open its dropped normal document file and execute the OSX backdoor

More information on this vulnerability can be found below:

  • http://about-threats.trendmicro.com/us/archive/vulnerability.aspx?name=(ms09-027)%20vulnerabilities%20in%20microsoft%20office%20word%20could%20allow%20remote%20code%20execution%20(969514)

  SOLUTION

Minimum Scan Engine:

9.300

FIRST VSAPI PATTERN FILE:

9.724.06

FIRST VSAPI PATTERN DATE:

14 Feb 2013

VSAPI OPR PATTERN File:

9.725.00

VSAPI OPR PATTERN Date:

14 Feb 2013

Step 1

Scan your computer with your Trend Micro product to delete files detected as TROJ_MDROP.AIK. 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 2

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.

NOTES:

To delete the dropped file:

  1. Open a Terminal window. To open a terminal window, double-click "Applications > Utilities > Terminal" in Finder.
  2. In the Terminal window, type the following command:

    rm /tmp/l
    rm /tmp/l.doc
    rm /tmp/l.sh
  3. Close Terminal by pressing (Command) + Q.


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