Backdoor.Win64.COBEACON.OSLJEM

February 23, 2023
 Analysis by: Kim Benedict Victorio
 ALIASES:

Backdoor:Win64/CobaltStrike.NP!dha (MICROSOFT)

 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

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.

  TECHNICAL DETAILS

File Size:

19,456 bytes

File Type:

EXE

Memory Resident:

No

Initial Samples Received Date:

08 Feb 2023

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.

Other Details

This Backdoor does the following:

  • This backdoor creates an outbound pipe:
    • MSSE-{Random Number}-server
  • It connects to the created outbound pipe.
  • It connects to the following URL to download its component which it will load in its memory and perform its malicious routine:
    • http://{BLOCKED}.{BLOCKED}.5.65/YYQZ
    However, as of this writing, the said sites are inaccessible.

  SOLUTION

Minimum Scan Engine:

9.800

FIRST VSAPI PATTERN FILE:

18.234.04

FIRST VSAPI PATTERN DATE:

03 Feb 2023

VSAPI OPR PATTERN File:

18.235.00

VSAPI OPR PATTERN Date:

04 Feb 2023

Step 1

Trend Micro Predictive Machine Learning detects and blocks malware at the first sign of its existence, before it executes on your system. When enabled, your Trend Micro product detects this malware under the following machine learning name:

     
    • Troj.Win32.TRX.XXPE50FFF065

Step 2

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 3

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

[ 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 4

Scan your computer with your Trend Micro product to delete files detected as Backdoor.Win64.COBEACON.OSLJEM. 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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