Analysis by: Jemimah Mae Molina
ALIASES:

W64/Agent.MW!tr.bdr (FORTINET); Backdoor:Win64/Agent (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

Infection Channel: Dropped by other malware, Downloaded from the Internet, Hosted on website

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 hosted on a website and run when a user accesses the said website.

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

  TECHNICAL DETAILS

File Size: 214,528 bytes
File Type: DLL
Memory Resident: No
Initial Samples Received Date: 15 Oct 2017
Payload: Executes files, Hosted on web server

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 hosted on a website and run when a user accesses the said website.

Backdoor Routine

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

  • cmd$[command to execute] → executes an arbitrary command and retrieves the command results
  • upload$[path to file] → intercepts the uploaded data from the web server and saves it to a specified file
  • download$[path to file] → reads the contents of a specified file and sends the data to the C&C server

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: 13.942.04
FIRST VSAPI PATTERN DATE: 02 Feb 2018
VSAPI OPR PATTERN File: 13.943.00
VSAPI OPR PATTERN Date: 03 Feb 2018

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

Scan your computer with your Trend Micro product to delete files detected as BKDR64_RGDOOR.ZIFB-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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