Analysis by: John Donnie Celestre
ALIASES:

VB:Trojan.VBA.Downloader.LH (BITDEFENDER); VBA/TrojanDownloader.Agent.IDU trojan (NOD32)

 PLATFORM:

Windows

 OVERALL RISK RATING:
 REPORTED INFECTION:

  • Threat Type: File infector

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

This File infector 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 the downloaded files. As a result, malicious routines of the downloaded files are exhibited on the affected system. As of this writing, the said sites are inaccessible.

  TECHNICAL DETAILS

File Size: 34816 bytes
File Type: XLS
Initial Samples Received Date: 10 Aug 2018

Arrival Details

This File infector arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

Autostart Technique

This File infector drops the following file(s) in the Windows User Startup folder to enable its automatic execution at every system startup:

  • %User Startup%\boosting.xls (copy of itself)

(Note: %User Startup% is the current user's Startup folder, which is usually C:\Windows\Profiles\{user name}\Start Menu\Programs\Startup on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Start Menu\Programs\Startup on Windows NT, C:\Documents and Settings\{User name}\Start Menu\Programs\Startup on Windows XP, or C:\Users\{user name}\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Startup on Windows Vista, 7, and 8.)

Download Routine

This File infector connects to the following website(s) to download and execute a malicious file:

  • http://45.{BLOCKED}.{BLOCKED}.150/boost/boosting.exe -> saved as %Windows%\boosting.exe

It connects to the following URL(s) to download its configuration file:

  • http://45.{BLOCKED}.{BLOCKED}.150/boost/config.txt -> saved as %Windows%\config.txt

It then executes the downloaded files. As a result, malicious routines of the downloaded files are exhibited on the affected system.

As of this writing, the said sites are inaccessible.

Other Details

This File infector connects to the following URL(s) to check for an Internet connection:

  • www.163.com

It does the following:

  • Checks for the following process if is already running in the affected system:
    boosting.exe

  SOLUTION

Minimum Scan Engine: 9.850
FIRST VSAPI PATTERN FILE: 14.334.08
FIRST VSAPI PATTERN DATE: 22 Jun 2018
VSAPI OPR PATTERN File: 14.335.00
VSAPI OPR PATTERN Date: 23 Jun 2018

Step 1

Before doing any scans, Windows XP, Windows Vista, and Windows 7 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

Search and delete these files

[ Learn More ]
There may be some files that are hidden. Please make sure you check the Search Hidden Files and Folders checkbox in the "More advanced options" option to include all hidden files and folders in the search result.  
  • %Windows%\boosting.exe
  • %Windows%\config.txt
  • %User Startup%\boosting.xls

Step 5

Restart in normal mode and scan your computer with your Trend Micro product for files detected as X97M_DLOADR.NTH1. 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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