Analysis by: Paul Steven Nadera
 Modified by: Mohammed Malubay

ALIASES:

N/A

 PLATFORM:

Windows

 OVERALL RISK RATING:
 DAMAGE POTENTIAL:
 REPORTED INFECTION:
 SYSTEM IMPACT RATING:
 INFORMATION EXPOSURE:

  • Threat Type: Backdoor

  • Destructiveness: No

  • Encrypted:

  • 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 executes commands from a remote malicious user, effectively compromising the affected system.

  TECHNICAL DETAILS

File Size: 69,115 bytes
File Type: JS
Initial Samples Received Date: 19 Apr 2020
Payload: 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.

Backdoor Routine

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

  • Execute arbitrary commands
  • Create directories
  • Search directories for files
  • Upload files
  • Download files and save as .zip
  • Connect to database
  • Capture screen
  • Collect driver information
  • Manipulate files:
    • Open
    • Read
    • Save
    • Create
    • Write
    • Delete
    • Rename

Information Theft

This Backdoor gathers the following data:

  • Computer Name
  • Username
  • User domain
  • Available Processors
  • Local host name and local address
  • Drive information (free space, total space)
  • Environment information
  • File details
  • Protocol being utilized
  • Server information
  • Java details
  • Remote host name, address, and username

Other Details

This Backdoor requires being hosted on a web server in order to proceed with its intended routine.

  SOLUTION

Minimum Scan Engine: 9.850
FIRST VSAPI PATTERN FILE: 15.814.04
FIRST VSAPI PATTERN DATE: 19 Apr 2020
VSAPI OPR PATTERN File: 15.815.00
VSAPI OPR PATTERN Date: 20 Apr 2020

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

Close all opened browser windows

Step 3

Scan your computer with your Trend Micro product to delete files detected as Backdoor.Java.WEBSHELL.SBJKSX. 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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