OSX_KEYDNAP.J

July 06, 2017
 Analysis by: Jeanne Jocson
 ALIASES:

OSX/Keydnap.A (NOD32), Backdoor:MacOS_X/Keydnap.A (Microsoft)

 PLATFORM:

Mac OS X

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

  • Threat Type: Backdoor

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Downloaded from the Internet, Dropped by other malware

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 may be dropped by other malware.

It steals certain information from the system and/or the user.

  TECHNICAL DETAILS

File Size:

3,035,136 bytes

File Type:

Mach-O

Memory Resident:

Yes

Initial Samples Received Date:

15 Sep 2016

Payload:

Steals information, Compromises system security

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.

It may be dropped by the following malware:

  • OSX_DROPPER.A

Installation

This Backdoor adds the following processes:

  • icloudproc
  • License.rtf
  • icloudsyncd
  • /usr/libexec/icloudsyncd -launchd netlogon.bundle

Backdoor Routine

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

  • http://{BLOCKED}citdpqa7tv.onion/api/osx

Dropping Routine

This Backdoor drops the following files:

  • /Applications/Transmission.app/Contents/Resources/License.rtf
  • /Volumes/Transmission/Transmission.app/Contents/Resources/License.rtf
  • $HOME/Library/Application Support/com.apple.iCloud.sync.daemon/icloudsyncd
  • $HOME/Library/Application Support/com.apple.iCloud.sync.daemon/process.id
  • $HOME/Library/LaunchAgents/com.apple.iCloud.sync.daemon.plist
  • /Library/Application Support/com.apple.iCloud.sync.daemon/
  • $HOME/Library/LaunchAgents/com.geticloud.icloud.photo.plist

Information Theft

This Backdoor steals the following information:

  • Keychain credentials

Other Details

This Backdoor does the following:

  • Uses local TOR as proxy
  • Uses a legitimate code signing key for the malicious Transmission application bundle
  • It has the following capabilities:
    • -download/upload files
    • -create processes
    • -update self
    • -steal user credentials

  SOLUTION

Minimum Scan Engine:

9.800

FIRST VSAPI PATTERN FILE:

12.778.06

FIRST VSAPI PATTERN DATE:

15 Sep 2016

VSAPI OPR PATTERN File:

12.779.00

VSAPI OPR PATTERN Date:

16 Sep 2016

Note that not all files, folders, and registry keys and entries are installed on your computer during this malware's/spyware's/grayware's execution. This may be due to incomplete installation or other operating system conditions. If you do not find the same files/folders/registry information, please proceed to the next step.

NOTES:

Terminate a malware/grayware process. This step allows you to disable the process files running in memory in preparation for the next steps.

  • icloudproc
  • License.rtf
  • icloudsyncd
  • /usr/libexec/icloudsyncd -launchd netlogon.bundle

Search and delete these files:

  • /Applications/Transmission.app/Contents/Resources/License.rtf
  • /Volumes/Transmission/Transmission.app/Contents/Resources/License.rtf
  • $HOME/Library/Application Support/com.apple.iCloud.sync.daemon/icloudsyncd
  • $HOME/Library/Application Support/com.apple.iCloud.sync.daemon/process.id
  • $HOME/Library/LaunchAgents/com.apple.iCloud.sync.daemon.plist
  • /Library/Application Support/com.apple.iCloud.sync.daemon/
  • $HOME/Library/LaunchAgents/com.geticloud.icloud.photo.plist

    Scan your computer with your Trend Micro product to delete files detected as OSX_KEYDNAP.J. 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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