Analysis by: Christopher Daniel So
 PLATFORM:

Mac OS X

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

  • Threat Type: Backdoor

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

Infection Channel: Dropped by other malware, Downloaded from the Internet

This backdoor, which runs on Linux and Mac, is designed to steal passwords stored by a number of popular Internet applications.

To get a one-glance comprehensive view of the behavior of this Backdoor, refer to the Threat Diagram shown below.

This Backdoor 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 commands from a remote malicious user, effectively compromising the affected system.

  TECHNICAL DETAILS

File Size: 78,664 bytes
File Type: Mach-O
Memory Resident: Yes
Initial Samples Received Date: 24 Aug 2012
Payload: Connects to URLs/IPs

Arrival Details

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

Backdoor Routine

This Backdoor executes the following commands from a remote malicious user:

  • Get OS version, user name, host name, $PATH variable, home directory, malware process ID, current process path
  • Download a file and save it as /tmp/{random file name 1}, then execute the downloaded file
  • Exit
  • List files in a directory
  • Read a file
  • Write and close a file
  • Copy a file
  • Execute a file
  • Rename a file
  • Delete a file
  • Create a directory
  • Start remote shell
  • Kill a process
  • Get currently logged in users
  • Enumerate window titles of all processes
  • Download a file and save it as /tmp/{random file name 2}
  • Simulate keyboard press
  • Simulate mouse event
  • Get stored login credentials in Thunderbird, SeaMonkey, Mozilla Firefox

It connects to the following URL(s) to send and receive commands from a remote malicious user:

  • {BLOCKED}.{BLOCKED}.208.65:4141

  SOLUTION

Minimum Scan Engine: 9.200
FIRST VSAPI PATTERN FILE: 9.346.05
FIRST VSAPI PATTERN DATE: 24 Aug 2012
VSAPI OPR PATTERN File: 9.347.00
VSAPI OPR PATTERN Date: 25 Aug 2012

NOTES:

Step 1

Scan your computer with your Trend Micro product and note files detected as OSX_NETWRD.A

Step 2. Terminating the malware process

To terminate the malware process:

  1. Open a Terminal window and list all running processes by typing the following command:
    ps –A
  2. In the list of processes, look for the file detected earlier. Note the process ID of the malware process.
  3. Type the following command:
    kill {malware process ID}
  4. Close the Terminal window.

Step 3. Scan your computer with your Trend Micro product to delete files detected as OSX_NETWRD.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.


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