Trojan.Win32.DLAUNCHER.A

 Analysis by: Raymart Christian Yambot

 ALIASES:

Win32:MalwareX-gen [Trj] (AVAST)

 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:

Downloaded from the Internet, Dropped by other malware

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:

2,343,936 bytes

Memory Resident:

Yes

Initial Samples Received Date:

17 Mar 2023

Payload:

Connects to URLs/IPs, Collects system information, Drops files, Deletes files, Terminates processes, Modifies system registry, Creates 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.

Installation

This Trojan drops the following files:

  • %All Users Profile%\SymantecSEndponit\Data\EdrEpmpCStorages.dat → Detected as Trojan.Win32.DBUNDLE.A
  • %All Users Profile%\SymantecSEndponit\Data\PchEpmpCStorages.dat → Detected as Trojan.Win32.DBUNDLE.A
  • %All Users Profile%\SymantecSEndponit\Data\csdkset.dat → Detected as Trojan.Win32.DBUNDLE.A
  • %All Users Profile%\SymantecSEndponit\Data\prodcltdef.dat → Detected as Trojan.Win32.DBUNDLE.A
  • %All Users Profile%\SymantecSEndponit\Bin\Symantec.exe
  • %All Users Profile%\SymantecSEndponit\Bin\LDVPOCX.OCX
  • %All Users Profile%\SymantecSEndponit\Bin\3.8.2259.42.manifest
  • %All Users Profile%\SymantecSEndponit\Bin\vivaldi_elf.dll
  • %All Users Profile%\SymantecSEndponit\Bin\vivaldi.exe
  • %All Users Profile%\Vivaldi\Application\3.8.2259.42.manifest
  • %All Users Profile%\Vivaldi\Application\vivaldi_elf.dll
  • %AppDataLocal%\Cyber\CUZ.exe
  • %All Users Profile%\Vivaldi\Application\vivaldi.exe
  • %AppDataLocal%\Cyber\ZIPDLL.dll
  • %AppDataLocal%\MicrosoftExplorer\msexpert.exe
  • %Application Data%\Microsoft\Crypto\RSA\{SID}\{Random Characters}_{Machine GUID}
  • %AppDataLocal%\MicrosoftExplorer\ZIPDLL.DLL → deleted afterward
  • %Public%\winmine.bin → deleted afterward

(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). . %AppDataLocal% is the Local Application Data folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Local on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).. %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Roaming on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).. %Public% is the folder that serves as a repository of files or folders common to all users, which is usually C:\Users\Public in Windows Vista, 7, and 8.)

It adds the following processes:

  • %System Root%\kaspersky\Usb Drive\3.0\Symantec.cmd
  • %All Users Profile%\SymantecSEndponit\Bin\Symantec.exe
  • cmd /c "%All Users Profile%\Vivaldi\Application\vivaldi.exe" {0-100}
  • "%AppDataLocal%/MicrosoftExplorer/msexpert.exe" {0-100} {Key for decrpyting shellcode}
  • "%AppDataLocal%\Cyber\CUZ.exe" "%AppDataLocal%/MicrosoftExplorer/msexpert.exe"

(Note: %System Root% is the Windows root folder, where it usually is C:\ on all Windows operating system versions.. %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). . %AppDataLocal% is the Local Application Data folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Local on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)

It creates the following folders:

  • %All Users Profile%\SymantecSEndponit\Bin
  • %All Users Profile%\SymantecSEndponit\Data

(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). )

It adds the following mutexes to ensure that only one of its copies runs at any one time:

  • FHSHIFEUI23436iuEIUIfdEuihif

Autostart Technique

This Trojan adds the following registry entries to enable its automatic execution at every system startup:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
SNMELSEILYWGUSJGS = "%All Users Profile%\SymantecSEndponit\Bin\Symantec.exe"

Other System Modifications

This Trojan deletes the following folders:

  • %All Users Profile%\Symantecs\SymantecXgp

(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). )

It modifies the following registry entries to hide files with Hidden attributes:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
Hidden = 2

(Note: The default value data of the said registry entry is 1.)

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
HideFileExt = 1

(Note: The default value data of the said registry entry is 0.)

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
ShowSuperHidden = 0

(Note: The default value data of the said registry entry is 1.)

Backdoor Routine

This Trojan connects to the following URL(s) to send and receive commands from a remote malicious user:

  • {BLOCKED}.{BLOCKED}.{BLOCKED}.116

Process Termination

This Trojan terminates the following processes if found running in the affected system's memory:

  • Symantec.exe

Information Theft

This Trojan gathers the following data:

  • Username
  • Computer name
  • System Architecture
  • Operating system
  • Available storage space of hard disk or flash drive

Stolen Information

This Trojan sends the gathered information via HTTP POST to the following URL:

  • {BLOCKED}.{BLOCKED}.{BLOCKED}.116/index.php

Other Details

This Trojan does the following:

  • It requires the following files to proceed to its intended routine:
    • %System Root%\kaspersky\Usb Drive\3.0\Symanted.cmd
    • %System Root%\kaspersky\Usb Drive\3.0\Data\EdrEpmpCStorages.dat
    • %System Root%\kaspersky\Usb Drive\3.0\Data\PchEpmpCStorages.dat
    • %System Root%\kaspersky\Usb Drive\3.0\Data\csdkset.dat
    • %System Root%\kaspersky\Usb Drive\3.0\Data\prodcltdef.dat
    • %System Root%\kaspersky\Usb Drive\3.0\LDVPOCX.OCX
  • If it detects that USB drives are connected to the system, it performs the following actions:
    • Existing files from the USB drive are moved to the following folder
      • {Drive root}\kaspersky\Usb Drive
  • It drops files with hidden attributes:
    • {Drive root}\kaspersky\Usb Drive\3.0\EdrEpmpCStorages.dat
    • {Drive root}\kaspersky\Usb Drive\3.0\PchEpmpCStorages.dat
    • {Drive root}\kaspersky\Usb Drive\3.0\csdkset.dat
    • {Drive root}\kaspersky\Usb Drive\3.0\prodcltdef.dat
    • {Drive root}\{USB drive name}.exe → Copy if itself
  • It creates the following folders:
    • {Drive root}\kaspersky\Usb Drive\3.0

(Note: %System Root% is the Windows root folder, where it usually is C:\ on all Windows operating system versions.)

  SOLUTION

Minimum Scan Engine:

9.800

FIRST VSAPI PATTERN FILE:

18.330.05

FIRST VSAPI PATTERN DATE:

20 Mar 2023

VSAPI OPR PATTERN File:

18.331.00

VSAPI OPR PATTERN Date:

21 Mar 2023

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

Restart in Safe Mode

[ Learn More ]

Step 3

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 4

Delete this registry value

[ Learn More ]

Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.

  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • SNMELSEILYWGUSJGS = "%All Users Profile%\SymantecSEndponit\Bin\Symantec.exe"

Step 5

Restore this modified registry value

[ Learn More ]

Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.

  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
    • Hidden = 2
    • Hidden = 1
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
    • HideFileExt = 1
    • HideFileExt = 0
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
    • ShowSuperHidden = 0
    • ShowSuperHidden = 1

Step 6

Search and delete this file

[ 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.
  • %System Root%\kaspersky\Usb Drive\3.0\Symanted.cmd
  • %System Root%\kaspersky\Usb Drive\3.0\LDVPOCX.OCX
  • %All Users Profile%\SymantecSEndponit\Data\EdrEpmpCStorages.dat
  • %All Users Profile%\SymantecSEndponit\Data\PchEpmpCStorages.dat
  • %All Users Profile%\SymantecSEndponit\Data\csdkset.dat
  • %All Users Profile%\SymantecSEndponit\Data\prodcltdef.dat
  • %All Users Profile%\SymantecSEndponit\Bin\Symantec.exe
  • %All Users Profile%\SymantecSEndponit\Bin\LDVPOCX.OCX
  • %All Users Profile%\SymantecSEndponit\Bin\3.8.2259.42.manifest
  • %All Users Profile%\SymantecSEndponit\Bin\vivaldi_elf.dll
  • %All Users Profile%\SymantecSEndponit\Bin\vivaldi.exe
  • %All Users Profile%\Vivaldi\Application\3.8.2259.42.manifest
  • %All Users Profile%\Vivaldi\Application\vivaldi_elf.dll
  • %System Root%\kaspersky\Usb Drive\3.0\Symanted.cmd
  • %System Root%\kaspersky\Usb Drive\3.0\Data\EdrEpmpCStorages.dat
  • %System Root%\kaspersky\Usb Drive\3.0\Data\PchEpmpCStorages.dat
  • %System Root%\kaspersky\Usb Drive\3.0\Data\csdkset.dat
  • %System Root%\kaspersky\Usb Drive\3.0\Data\prodcltdef.dat
  • %AppDataLocal%\Cyber\CUZ.exe
  • %All Users Profile%\Vivaldi\Application\vivaldi.exe
  • %AppDataLocal%\Cyber\ZIPDLL.dll
  • %AppDataLocal%\MicrosoftExplorer\msexpert.exe
  • %Application Data%\Microsoft\Crypto\RSA\{SID}\{Random Characters}_{Machine GUID}
  • %AppDataLocal%\MicrosoftExplorer\ZIPDLL.DLL
  • %Public%\winmine.bin
  • {Drive root}\kaspersky\Usb Drive\3.0\EdrEpmpCStorages.dat
  • {Drive root}\kaspersky\Usb Drive\3.0\PchEpmpCStorages.dat
  • {Drive root}\kaspersky\Usb Drive\3.0\csdkset.dat
  • {Drive root}\kaspersky\Usb Drive\3.0\prodcltdef.dat
  • {Drive root}\{USB drive name}.exe

Step 7

Search and delete these folders

[ Learn More ]
Please make sure you check the Search Hidden Files and Folders checkbox in the More advanced options option to include all hidden folders in the search result.
  • %All Users Profile%\SymantecSEndponit\Bin
  • %All Users Profile%\SymantecSEndponit\Data
  • {Drive root}\kaspersky\Usb Drive\3.0

Step 8

Restart in normal mode and scan your computer with your Trend Micro product for files detected as Trojan.Win32.DLAUNCHER.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 this Knowledge Base page for more information.


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