Analysis by: Byron Jon Gelera
 PLATFORM:

Windows

 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: Dropped by other malware, Downloaded from the Internet

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 does not have any propagation routine.

It executes commands from a remote malicious user, effectively compromising the affected system. It connects to a website to send and receive information.

  TECHNICAL DETAILS

File Size: 49,321 bytes
File Type: DLL
Memory Resident: Yes
Initial Samples Received Date: 30 Nov 2017
Payload: Connects to URLs/IPs, Steals information

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.

Propagation

This Backdoor does not have any propagation routine.

Backdoor Routine

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

  • Perform Remote Shell Commands
  • Read\Upload Arbitrary File
  • Download Arbitrary File
  • Terminate Itself

It connects to the following websites to send and receive information:

  • https://api.{BLOCKED}xapi.com/2/files/create_folder
  • https://api.{BLOCKED}xapi.com/2/files/delete
  • https://api.{BLOCKED}xapi.com/2/files/get_metadata
  • https://api.{BLOCKED}xapi.com/2/files/list_folder
  • https://content.{BLOCKED}xapi.com/2/files/upload
  • https://content.{BLOCKED}xapi.com/2/files/download

Information Theft

This Backdoor gathers the following data:

  • Host Name
  • IP Address
  • Mac Address

Other Details

This Backdoor requires the existence of the following files to properly run:

  • {Malware Path}\Crypt_base.dat

  SOLUTION

Minimum Scan Engine: 9.850
FIRST VSAPI PATTERN FILE: 13.826.06
FIRST VSAPI PATTERN DATE: 06 Dec 2017
VSAPI OPR PATTERN File: 13.827.00
VSAPI OPR PATTERN Date: 07 Dec 2017

Step 1

Before doing any scans, Windows XP, Windows Vista, and Windows 7 users must disable System Restore to allow full scanning of their computers.

Step 2

Identify and terminate files detected as BKDR_TAILDR.ZTEK-A

[ Learn More ]
  1. Windows Task Manager may not display all running processes. In this case, please use a third-party process viewer, preferably Process Explorer, to terminate the malware/grayware/spyware file. You may download the said tool here.
  2. If the detected file is displayed in either Windows Task Manager or Process Explorer but you cannot delete it, restart your computer in safe mode. To do this, refer to this link for the complete steps.
  3. If the detected file is not displayed in either Windows Task Manager or Process Explorer, continue doing the next steps.

Step 3

Scan your computer with your Trend Micro product to delete files detected as BKDR_TAILDR.ZTEK-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 the following Trend Micro Support pages for more information:


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