Analysis by: Karen Ivy Titiwa
ALIASES:

HEUR:Trojan.Win32.Generic(KASPERSKY); Backdoor.Cobalt!gen3(NORTON)

 PLATFORM:

Windows

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

  • Threat Type: Backdoor

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

Infection Channel: 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 executes commands from a remote malicious user, effectively compromising the affected system.

  TECHNICAL DETAILS

File Size: 285,696 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 19 Aug 2020
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.

Installation

This Backdoor adds the following processes:

  • %System%\rundll32.exe

(Note: %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.)

It injects codes into the following process(es):

  • created rundll32.exe process

Backdoor Routine

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

  • Execute arbitrary commands
  • Manage files/directories
  • Manage processes
  • Manage services
  • Upload files
  • Download files
  • Connect to named pipes
  • Use/purge Kerberos tickets
  • Enumerate registries

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

  • {BLOCKED}.{BLOCKED}.41.29

Information Theft

Upon execution of the affected application, it gathers the following information:

  • User name
  • Computer name
  • IP address
  • OS version

Other Details

This Backdoor does the following:

  • This malware starts the following service:
    • DceRpcSs
  • It creates a named pipe called MSSE-{Random number}-server.

  SOLUTION

Minimum Scan Engine: 9.850
FIRST VSAPI PATTERN FILE: 16.176.07
FIRST VSAPI PATTERN DATE: 20 Aug 2020
VSAPI OPR PATTERN File: 16.177.00
VSAPI OPR PATTERN Date: 21 Aug 2020

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.XXPE50FFF036

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

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 4

Disable this malware service

[ Learn More ]
    • DceRpcSs

Step 5

Restart in normal mode and scan your computer with your Trend Micro product for files detected as Backdoor.Win32.COBEACON.AAH-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.


Did this description help? Tell us how we did.