Analysis by: Emilio Marcel Garcia
ALIASES:

MSOffice/EncBook.B!tr (FORTINET); HEUR:Trojan-Downloader.MSOffice.SLoad.gen (KASPERSKY)

 PLATFORM:

Windows

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

Infection Channel: Spammed via email

This Trojan arrives as an attachment to email messages spammed by other malware/grayware or malicious users.

As of this writing, the said sites are inaccessible.

  TECHNICAL DETAILS

File Size: 285,184 bytes
File Type: XLS
Memory Resident: No
Initial Samples Received Date: 15 Apr 2020
Payload: Connects to URLs/IPs

Arrival Details

This Trojan arrives as an attachment to email messages spammed by other malware/grayware or malicious users.

Installation

This Trojan adds the following processes:

  • %All Users Profile%\qmbvlcq.exe

(Note: %All Users Profile% is the common user's profile folder, which is usually C:\Documents and Settings\All Users on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\ProgramData on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit). )

Download Routine

This Trojan accesses the following websites to download files:

  • https://www.{BLOCKED}contracting.com/ray/pom.php

It saves the files it downloads using the following names:

  • %All Users Profile%\qmbvlcq.exe -> detected as TrojanSpy.Win32.URSNIF.THDAEBO

(Note: %All Users Profile% is the common user's profile folder, which is usually C:\Documents and Settings\All Users on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\ProgramData on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit). )

As of this writing, the said sites are inaccessible.

  SOLUTION

Minimum Scan Engine: 9.850
FIRST VSAPI PATTERN FILE: 15.808.03
FIRST VSAPI PATTERN DATE: 16 Apr 2020
VSAPI OPR PATTERN File: 15.809.00
VSAPI OPR PATTERN Date: 17 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

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.  
  • %All Users Profile%\qmbvlcq.exe

Step 5

Restart in normal mode and scan your computer with your Trend Micro product for files detected as Trojan.X97M.URSNIF.THDAEBO. 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.