Analysis by: Mc Justine De Guzman
 PLATFORM:

Windows

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

  • Threat Type: Backdoor

  • Destructiveness: No

  • Encrypted: No

  • 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 may be downloaded by other malware/grayware from remote sites.

It connects to a website to send and receive information.

  TECHNICAL DETAILS

File Size: 2,142,300 bytes
File Type: DLL
Memory Resident: No
Initial Samples Received Date: 08 Sep 2021
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.

It may be downloaded by the following malware/grayware from remote sites:

  • Trojan.HTML.COBEACON.F

Installation

This Backdoor adds the following processes:

  • powershell -c "Sleep 5 ; Remove-Item -Path "" -Force -> to delete itself

It injects codes into the following process(es):

  • %Program Files%\Windows Photo Viewer\ImagingDevices.exe
  • %Program Files%\Windows Mail\wabmig.exe
  • %Program Files%\Windows Mail\wab.exe

(Note: %Program Files% is the default Program Files folder, usually C:\Program Files in Windows 2000(32-bit), Server 2003(32-bit), XP, Vista(64-bit), 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit) , or C:\Program Files (x86) in Windows XP(64-bit), Vista(64-bit), 7(64-bit), 8(64-bit), 8.1(64-bit), 2008(64-bit), 2012(64-bit) and 10(64-bit).)

Backdoor Routine

This Backdoor connects to the following websites to send and receive information:

  • https://{BLOCKED}f.com/get_load
  • https://{BLOCKED}h.com/ml.html
  • https://{BLOCKED}u.com/hr.html

  SOLUTION

Minimum Scan Engine: 9.800
FIRST VSAPI PATTERN FILE: 16.956.01
FIRST VSAPI PATTERN DATE: 08 Sep 2021
VSAPI OPR PATTERN File: 16.957.00
VSAPI OPR PATTERN Date: 09 Sep 2021

Step 1

Before doing any scans, Windows 7, Windows 8, Windows 8.1, and Windows 10 users must disable System Restore to allow full scanning of their computers.

Step 2

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.

Step 3

Restart in Safe Mode

[ Learn More ]

Step 4

Identify and terminate files detected as Backdoor.Win64.COBEACON.OSLJAU

[ 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 5

Restart in normal mode and scan your computer with your Trend Micro product for files detected as Backdoor.Win64.COBEACON.OSLJAU. 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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