arrow_back
search
close

Trojan.Win32.MALREP.THDODBO

April 04, 2020
 PLATFORM:

Windows

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

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.

It drops files as ransom note.

  TECHNICAL DETAILS

File Size:

16,384 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

04 Apr 2020

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 adds the following processes:

  • "%Windows%\delog.bat"
  • %Windows%\delog.bat
  • %System%\cmd.exe /c bcdedit
  • %System%\cmd.exe /c wevtutil.exe el
  • wevtutil.exe cl "Analytic"
  • wevtutil.exe cl "Application"
  • wevtutil.exe cl "DirectShowFilterGraph"
  • wevtutil.exe cl "DirectShowPluginControl"
  • wevtutil.exe cl "Els_Hyphenation/Analytic"
  • wevtutil.exe cl "EndpointMapper"
  • wevtutil.exe cl "ForwardedEvents"
  • wevtutil.exe cl "HardwareEvents"
  • wevtutil.exe cl "Internet Explorer"
  • wevtutil.exe cl "Key Management Service"
  • wevtutil.exe cl "MF_MediaFoundationDeviceProxy"
  • wevtutil.exe cl "Media Center"
  • wevtutil.exe cl "MediaFoundationDeviceProxy"
  • wevtutil.exe cl "MediaFoundationPerformance"
  • wevtutil.exe cl "MediaFoundationPipeline"
  • wevtutil.exe cl "MediaFoundationPlatform"
  • wevtutil.exe cl "Microsoft-IE/Diagnostic"
  • wevtutil.exe cl "Microsoft-IEDVTOOL/Diagnostic"
  • wevtutil.exe cl "Microsoft-IEFRAME/Diagnostic"
  • wevtutil.exe cl "Microsoft-JSDumpHeap/Diagnostic"
  • wevtutil.exe cl "Microsoft-PerfTrack-IEFRAME/Diagnostic"
  • wevtutil.exe cl "Microsoft-PerfTrack-MSHTML/Diagnostic"
  • wevtutil.exe cl "Microsoft-Windows-ADSI/Debug"
  • wevtutil.exe cl "Microsoft-Windows-API-Tracing/Operational"
  • wevtutil.exe cl "Microsoft-Windows-ATAPort/General"
  • wevtutil.exe cl "Microsoft-Windows-ATAPort/SATA-LPM"
  • wevtutil.exe cl "Microsoft-Windows-ActionQueue/Analytic"
  • wevtutil.exe cl "Microsoft-Windows-AltTab/Diagnostic"
  • wevtutil.exe cl "Microsoft-Windows-AppID/Operational"
  • wevtutil.exe cl "Microsoft-Windows-AppLocker/EXE and DLL"
  • wevtutil.exe cl "Microsoft-Windows-AppLocker/MSI and Script"
  • wevtutil.exe cl "Microsoft-Windows-Application Server-Applications/Admin"
  • wevtutil.exe cl "Microsoft-Windows-Application Server-Applications/Analytic"
  • wevtutil.exe cl "Microsoft-Windows-Application Server-Applications/Debug"
  • wevtutil.exe cl "Microsoft-Windows-Application Server-Applications/Operational"
  • wevtutil.exe cl "Microsoft-Windows-Application-Experience/Problem-Steps-Recorder"
  • wevtutil.exe cl "Microsoft-Windows-Application-Experience/Program-Compatibility-Assistant"
  • wevtutil.exe cl "Microsoft-Windows-Application-Experience/Program-Compatibility-Troubleshooter"
  • wevtutil.exe cl "Microsoft-Windows-Application-Experience/Program-Inventory"
  • wevtutil.exe cl "Microsoft-Windows-Application-Experience/Program-Inventory/Debug"
  • wevtutil.exe cl "Microsoft-Windows-Application-Experience/Program-Telemetry"
  • wevtutil.exe cl "Microsoft-Windows-Audio/CaptureMonitor"
  • wevtutil.exe cl "Microsoft-Windows-Audio/Operational"
  • wevtutil.exe cl "Microsoft-Windows-Audio/Performance"
  • wevtutil.exe cl "Microsoft-Windows-Audit/Analytic"
  • wevtutil.exe cl "Microsoft-Windows-Authentication User Interface/Operational"
  • wevtutil.exe cl "Microsoft-Windows-AxInstallService/Log"
  • wevtutil.exe cl "Microsoft-Windows-Backup"
  • wevtutil.exe cl "Microsoft-Windows-Biometrics/Operational"
  • wevtutil.exe cl "Microsoft-Windows-BitLocker-DrivePreparationTool/Admin"
  • wevtutil.exe cl "Microsoft-Windows-BitLocker-DrivePreparationTool/Operational"
  • wevtutil.exe cl "Microsoft-Windows-Bits-Client/Analytic"
  • wevtutil.exe cl "Microsoft-Windows-Bits-Client/Operational"
  • wevtutil.exe cl "Microsoft-Windows-Bluetooth-MTPEnum/Operational"
  • wevtutil.exe cl "Microsoft-Windows-BranchCache/Operational"
  • wevtutil.exe cl "Microsoft-Windows-BranchCacheClientEventProvider/Diagnostic"
  • wevtutil.exe cl "Microsoft-Windows-BranchCacheEventProvider/Diagnostic"
  • wevtutil.exe cl "Microsoft-Windows-BranchCacheSMB/Analytic"
  • wevtutil.exe cl "Microsoft-Windows-BranchCacheSMB/Operational"
  • wevtutil.exe cl "Microsoft-Windows-CAPI2/Operational"
  • wevtutil.exe cl "Microsoft-Windows-CDROM/Operational"
  • wevtutil.exe cl "Microsoft-Windows-COM/Analytic"
  • wevtutil.exe cl "Microsoft-Windows-COMRuntime/Tracing"
  • wevtutil.exe cl "Microsoft-Windows-Calculator/Debug"
  • wevtutil.exe cl "Microsoft-Windows-Calculator/Diagnostic"
  • wevtutil.exe cl "Microsoft-Windows-CertPoleEng/Operational"
  • wevtutil.exe cl "Microsoft-Windows-CertificateServicesClient-CredentialRoaming/Operational"
  • wevtutil.exe cl "Microsoft-Windows-ClearTypeTextTuner/Diagnostic"
  • wevtutil.exe cl "Microsoft-Windows-CmiSetup/Analytic"
  • wevtutil.exe cl "Microsoft-Windows-CodeIntegrity/Operational"
  • wevtutil.exe cl "Microsoft-Windows-CodeIntegrity/Verbose"
  • wevtutil.exe cl "Microsoft-Windows-ComDlg32/Analytic"
  • wevtutil.exe cl "Microsoft-Windows-ComDlg32/Debug"
  • wevtutil.exe cl "Microsoft-Windows-CorruptedFileRecovery-Client/Operational"
  • wevtutil.exe cl "Microsoft-Windows-CorruptedFileRecovery-Server/Operational"
  • wevtutil.exe cl "Microsoft-Windows-CredUI/Diagnostic"
  • wevtutil.exe cl "Microsoft-Windows-Crypto-RNG/Analytic"
  • wevtutil.exe cl "Microsoft-Windows-D3D10Level9/Analytic"
  • wevtutil.exe cl "Microsoft-Windows-D3D10Level9/PerfTiming"
  • wevtutil.exe cl "Microsoft-Windows-DCLocator/Debug"
  • wevtutil.exe cl "Microsoft-Windows-DNS-Client/Operational"
  • wevtutil.exe cl "Microsoft-Windows-DUI/Diagnostic"
  • wevtutil.exe cl "Microsoft-Windows-DUSER/Diagnostic"
  • wevtutil.exe cl "Microsoft-Windows-DXGI/Analytic"
  • wevtutil.exe cl "Microsoft-Windows-DXGI/Logging"
  • wevtutil.exe cl "Microsoft-Windows-DXP/Analytic"
  • wevtutil.exe cl "Microsoft-Windows-DateTimeControlPanel/Analytic"
  • wevtutil.exe cl "Microsoft-Windows-DateTimeControlPanel/Debug"
  • wevtutil.exe cl "Microsoft-Windows-DateTimeControlPanel/Operational"
  • wevtutil.exe cl "Microsoft-Windows-Deplorch/Analytic"
  • wevtutil.exe cl "Microsoft-Windows-DeviceSync/Analytic"
  • wevtutil.exe cl "Microsoft-Windows-DeviceSync/Operational"
  • wevtutil.exe cl "Microsoft-Windows-DeviceUx/Informational"
  • wevtutil.exe cl "Microsoft-Windows-DeviceUx/Performance"
  • wevtutil.exe cl "Microsoft-Windows-Dhcp-Client/Admin"
  • wevtutil.exe cl "Microsoft-Windows-Dhcp-Client/Operational"
  • wevtutil.exe cl "Microsoft-Windows-DhcpNap/Admin"
  • wevtutil.exe cl "Microsoft-Windows-DhcpNap/Operational"
  • wevtutil.exe cl "Microsoft-Windows-Dhcpv6-Client/Admin"
  • wevtutil.exe cl "Microsoft-Windows-Dhcpv6-Client/Operational"
  • wevtutil.exe cl "Microsoft-Windows-DiagCpl/Debug"
  • wevtutil.exe cl "Microsoft-Windows-Diagnosis-DPS/Analytic"
  • wevtutil.exe cl "Microsoft-Windows-Diagnosis-DPS/Debug"
  • wevtutil.exe cl "Microsoft-Windows-Diagnosis-DPS/Operational"
  • wevtutil.exe cl "Microsoft-Windows-Diagnosis-MSDE/Debug"
  • wevtutil.exe cl "Microsoft-Windows-Diagnosis-PCW/Analytic"
  • wevtutil.exe cl "Microsoft-Windows-Diagnosis-PCW/Debug"
  • wevtutil.exe cl "Microsoft-Windows-Diagnosis-PCW/Operational"
  • wevtutil.exe cl "Microsoft-Windows-Diagnosis-PLA/Debug"
  • wevtutil.exe cl "Microsoft-Windows-Diagnosis-PLA/Operational"
  • wevtutil.exe cl "Microsoft-Windows-Diagnosis-Perfhost/Analytic"
  • wevtutil.exe cl "Microsoft-Windows-Diagnosis-Scheduled/Operational"
  • wevtutil.exe cl "Microsoft-Windows-Diagnosis-Scripted/Admin"
  • wevtutil.exe cl "Microsoft-Windows-Diagnosis-Scripted/Analytic"
  • wevtutil.exe cl "Microsoft-Windows-Diagnosis-Scripted/Debug"
  • wevtutil.exe cl "Microsoft-Windows-Diagnosis-Scripted/Operational"
  • wevtutil.exe cl "Microsoft-Windows-Diagnosis-ScriptedDiagnosticsProvider/Debug"
  • wevtutil.exe cl "Microsoft-Windows-Diagnosis-ScriptedDiagnosticsProvider/Operational"
  • wevtutil.exe cl "Microsoft-Windows-Diagnosis-TaskManager/Debug"
  • wevtutil.exe cl "Microsoft-Windows-Diagnosis-WDC/Analytic"
  • wevtutil.exe cl "Microsoft-Windows-Diagnosis-WDI/Debug"
  • wevtutil.exe cl "Microsoft-Windows-Diagnostics-Networking/Debug"
  • wevtutil.exe cl "Microsoft-Windows-Diagnostics-Networking/Operational"
  • wevtutil.exe cl "Microsoft-Windows-Diagnostics-PerfTrack-Counters/Diagnostic"
  • wevtutil.exe cl "Microsoft-Windows-Diagnostics-PerfTrack/Diagnostic"
  • wevtutil.exe cl "Microsoft-Windows-Diagnostics-Performance/Diagnostic"
  • wevtutil.exe cl "Microsoft-Windows-Diagnostics-Performance/Diagnostic/Loopback"
  • wevtutil.exe cl "Microsoft-Windows-Diagnostics-Performance/Operational"
  • wevtutil.exe cl "Microsoft-Windows-Direct3D10/Analytic"
  • wevtutil.exe cl "Microsoft-Windows-Direct3D10_1/Analytic"

(Note: %Windows% is the Windows folder, where it usually is C:\Windows on all Windows operating system versions.. %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.)

Other System Modifications

This Trojan deletes the following files:

  • %System Root%\AVScanner.ini
  • %System Root%\Email and Password List.js
  • %System Root%\Email and Password List.htm
  • %System Root%\Email and Password List.vbs
  • %System Root%\2520.ini
  • %System Root%\Email and Password List.txt

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

It adds the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Policies\
System
EnableLUA = "1"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Policies\
System
ConsentPromptBehaviorAdmin = "0"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Policies\
System
PromptOnSecureDesktop = "0"

HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\
Microsoft\Windows\CurrentVersion\
Run
Autorun.SQL = "%Windows%\svhost.exe"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
.4ep3Zv0XAobY_RSA
(Default) = "EncriptIDfile"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
EncriptIDfile
(Default) = "data_recovery_soft@protonmail.com end JeryDark@tutanota.com"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
EncriptIDfile\Shell\Open\
Command
(Default) = "%Windows%\SysWOW64\mshta.exe %%System Root%\Data recovery.hta"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
EncriptIDfile\DefaultIcon
(Default) = "imageres.dll,54"

It modifies the following registry entries:

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Control\Windows
ErrorMode = "2"

It deletes the following registry keys:

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
.4ep3Zv0XAobY_RSA\(Default)

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
EncriptIDfile\(Default)

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
EncriptIDfile\Shell\Open\
Command\(Default)

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
EncriptIDfile\DefaultIcon\(Default)

Dropping Routine

This Trojan drops the following files:

  • %System Root%\Email and Password List.htm.4ep3Zv0XAobY_RSA
  • %System Root%\Email and Password List.vbs.4ep3Zv0XAobY_RSA
  • %System Root%\Email and Password List.js.4ep3Zv0XAobY_RSA
  • %System Root%\Email and Password List.txt.4ep3Zv0XAobY_RSA
  • %Windows%\delog.bat
  • %System Root%\AVScanner.ini.4ep3Zv0XAobY_RSA
  • %System Root%\2520.ini.4ep3Zv0XAobY_RSA
  • %Windows%\svhost.exe

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

Ransomware Routine

This Trojan drops the following file(s) as ransom note:

  • Data recovery.hta

This report is generated via an automated analysis system.

  SOLUTION

Minimum Scan Engine:

9.850

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

Identify and terminate files detected as Trojan.Win32.MALREP.THDODBO

[ Learn More ]
  1. Windows Task Manager may not display all running processes. In this case, please use a third-party process viewer, preferably Process Explorer, to terminate the malware/grayware/spyware file. You may download the said tool here.
  2. If the detected file is displayed in either Windows Task Manager or Process Explorer but you cannot delete it, restart your computer in safe mode. To do this, refer to this link for the complete steps.
  3. If the detected file is not displayed in either Windows Task Manager or Process Explorer, continue doing the next steps.

Step 3

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_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System
    • EnableLUA = "1"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System
    • ConsentPromptBehaviorAdmin = "0"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System
    • PromptOnSecureDesktop = "0"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\Windows\CurrentVersion\Run
    • Autorun.SQL = "%Windows%\svhost.exe"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\.4ep3Zv0XAobY_RSA
    • (Default) = "EncriptIDfile"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\EncriptIDfile
    • (Default) = "data_recovery_soft@protonmail.com end JeryDark@tutanota.com"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\EncriptIDfile\Shell\Open\Command
    • (Default) = "%Windows%\SysWOW64\mshta.exe %%System Root%\Data recovery.hta"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\EncriptIDfile\DefaultIcon
    • (Default) = "imageres.dll,54"

Step 4

Restore these modified registry values

[ Learn More ]

Important:Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this only if you know how to or you can seek your system administrator's help. You may also check out this Microsoft article first before modifying your computer's registry.

  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Control\Windows
    • ErrorMode = "2"

Step 5

Search and delete these components

[ Learn More ]
There may be some components 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%\Email and Password List.htm.4ep3Zv0XAobY_RSA
  • %System Root%\Email and Password List.vbs.4ep3Zv0XAobY_RSA
  • %System Root%\Email and Password List.js.4ep3Zv0XAobY_RSA
  • %System Root%\Email and Password List.txt.4ep3Zv0XAobY_RSA
  • %Windows%\delog.bat
  • %System Root%\AVScanner.ini.4ep3Zv0XAobY_RSA
  • %System Root%\2520.ini.4ep3Zv0XAobY_RSA
  • %Windows%\svhost.exe

Step 6

Scan your computer with your Trend Micro product to delete files detected as Trojan.Win32.MALREP.THDODBO. 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:

Step 7

Restore this file from backup only Microsoft-related files will be restored. If this malware/grayware also deleted files related to programs that are not from Microsoft, please reinstall those programs on you computer again.

  • %System Root%\AVScanner.ini
  • %System Root%\Email and Password List.js
  • %System Root%\Email and Password List.htm
  • %System Root%\Email and Password List.vbs
  • %System Root%\2520.ini
  • %System Root%\Email and Password List.txt

Step 8

Restore these deleted registry keys/values from backup

*Note: Only Microsoft-related keys/values will be restored. If the malware/grayware also deleted registry keys/values related to programs that are not from Microsoft, please reinstall those programs on your computer.

  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\.4ep3Zv0XAobY_RSA
    • (Default)
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\EncriptIDfile
    • (Default)
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\EncriptIDfile\Shell\Open\Command
    • (Default)
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\EncriptIDfile\DefaultIcon
    • (Default)


Did this description help? Tell us how we did.