OSX_STEALKYS.A

February 11, 2017
 Analysis by: David John Agni
 ALIASES:

Trojan.MAC.MacDownload.A (BitDefender), OSX.Addkeysteal (Symantec), OSX/MacDownloader.A (ESET-NOD32)

 PLATFORM:

Mac OS

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

  • Threat Type: Spyware

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Downloaded from the Internet

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

It connects to certain websites to send and receive information. However, as of this writing, the said sites are inaccessible.

  TECHNICAL DETAILS

File Size:

290,416 bytes

File Type:

Mach-O

Memory Resident:

No

Initial Samples Received Date:

07 Feb 2017

Payload:

Displays message/message boxes

Arrival Details

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

Information Theft

This spyware gathers the following data:

  • User's Keychains
  • OS Information
  • Running Processes
  • Installed Applications
  • Local IP
  • Ifconfig
  • Username Password

Stolen Information

This spyware saves the stolen information in the following file:

  • /tmp/applist.txt

Other Details

This spyware connects to the following website to send and receive information:

  • http://{BLOCKED}.{BLOCKED}.97.37/Servermac.php

However, as of this writing, the said sites are inaccessible.

NOTES:

This malware displays a fake Adobe Flash Player installer:

After the user clicked the Update Flash-Player it displays the following fake warning window:

After the user clicks OK, the malware displays the window below to obtain the password directly from the user:

After the user types the correct password, it displays the window:

  SOLUTION

Minimum Scan Engine:

9.850

FIRST VSAPI PATTERN FILE:

13.210.04

FIRST VSAPI PATTERN DATE:

08 Feb 2017

VSAPI OPR PATTERN File:

13.211.00

VSAPI OPR PATTERN Date:

09 Feb 2017

Step 1

Scan your computer with your Trend Micro product to clean files detected as OSX_STEALKYS.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 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/applist.txt


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