Analysis by: Rhena Inocencio
ALIASES:

Exploit:Win32/MS09-027 (Microsoft), Bloodhound.Olemacho (Symantec), Troj/DocOSXDr-B (Sophos)

 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

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.

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: 204,010 bytes
File Type: DOC
Initial Samples Received Date: 26 Apr 2013
Payload: Drops files

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.

Installation

This Trojan drops the following non-malicious file:

  • /tmp/l.doc - decoy document

Dropping Routine

This Trojan drops the following files:

  • /tmp/l.sh - opens /tmp/l.doc and executes /tmp/l
  • /tmp/l - detected as OSX_EXPLOIT.B

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

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

  SOLUTION

Minimum Scan Engine: 9.300
FIRST VSAPI PATTERN FILE: 9.878.08
FIRST VSAPI PATTERN DATE: 25 Apr 2013
VSAPI OPR PATTERN File: 9.879.00
VSAPI OPR PATTERN Date: 25 Apr 2013

Step 1

Remove malware/grayware files dropped/downloaded by TROJ_MDROP.OSX

    • OSX_EXPLOIT.B

Step 2

Search and delete these files

[ Learn More ]
There may be some 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.
  • /tmp/l.doc
  • /tmp/l.sh

Step 3

Scan your computer with your Trend Micro product to delete files detected as TROJ_MDROP.OSX. 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 4

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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