Trojan.Win64.VOOLS.AH

 Analysis by: Arvin Roi Macaraeg

 ALIASES:

BackDoor-FDWY!09263A2D37C1(NAI); Win32:Vools-B [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.

It does not have any backdoor routine.

It does not have any downloading capability.

  TECHNICAL DETAILS

File Size:

129,024 bytes

File Type:

DLL

Memory Resident:

No

Initial Samples Received Date:

03 Jun 2019

Payload:

Exploits vulnerabilities, Connects to URLs/IPs, Steals information

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:

  • %System%\dllhostex.exe <- Detected as Coinminer.Win64.TOOLXMR.SMA
  • %Windows%\NetworkDistribution\Diagnosis.txt <- archive file containing the EternalBlue and DoublePulsar

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

It creates the following folders:

  • %Windows%\NetworkDistribution

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

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

  • {B8A7AE22-7F59-CDE5-71F9C2A}
  • {EB0Z85-37F8-D529-B8783F}
  • {E2088B81F-2A96-43E8-B9F522B}
  • {E2077B81F-2A96-43E8-B9F522B}
  • {E2066B81F-2A96-43E8-B9F522B}
  • {E2044B81F-2A96-43E8-B9F522B}
  • {5EC0AC33D-E23D-C8A2-A92C833}
  • {CI59C45E-F19A-Z07C-565B17CO}
  • {6B2089804-F412-CB72-7C027E6}
  • {3EC1AC33D-E55D-C8A2-A92C822}
  • {N33821F9E-F215-34AA-721269D}
  • {F86E2D648-EF7B-6054-D43FC41}
  • {AE5C7574-0869-D969-AAC0353}
  • {B3DD887C-4738-EBD0-6CD0105}
  • {F5175396-40C2-0218-278D6EE}
  • {36FBBFAD-7376-931C-AB4DC42}
  • {56CF8FC1-3E2E-F825-8124BC6}
  • {F4BF5979-70D3-AF7E-8B6C38F}
  • {42885B26-80A7-2FF3-D2F8957}
  • {B512B75E-21A0-C34D-AF3FEE0}
  • {502CBAF5-55E5-F190-16321A4}
  • {CE9SCB-B92-FC8-A6FECD}
  • {KA1C25-978-BB7-510DEW}

It injects threads into the following normal process(es):

  • ".exe" available in the folder of %System%.

(Note: %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%\dllhostex.exe
  • %System%\TaskIndexer.exe

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

It adds the following registry entries as part of its installation routine:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\NetworkPlatform\
Location Awareness
LastBackup = {Hex Values}

Backdoor Routine

This Trojan does not have any backdoor routine.

Rootkit Capabilities

This Trojan does not have rootkit capabilities.

Process Termination

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

  • taskmgr.exe

Download Routine

This Trojan does not have any downloading capability.

Information Theft

This Trojan gathers the following data:

  • MAC Address
  • IP Address
  • Computer name
  • OS version
  • CPU and GPU name

Stolen Information

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

  • https://z.{BLOCKED}m.com/login.php?mac={mac address}&ip={ip address}&host={computer name}&tick={value}&os={os}&cpu={cpu}&gpu={gpu}

Other Details

This Trojan does the following:

  • It uses EternalBlue/DoublePulsar components to takes advantage of the following software vulnerabilities to distribute its component file across its network.
  • It checks if it is running as a service.
  • It checks if the following strings are used as its filename:
    • %System%\FunctionUPnPSystem.dll
  • It accesses, decrypts, and runs the following files:
    • %System%\rdpwvq.tlb
  • It deletes older version of itself:
    • %System%\vmichapagentsrv.dll
    • %System%\MaintenancesServices.dll
    • %System%\tpmagentservice.dll
    • %System%\wmassrv.dll
    • %System%\snmpstorsrv.dll
    • %System%\winhttpwebfoundationsvc.dll
  • It deletes older version of EternalBlue/DoublePulsar:
    • %Windows%\IME\Microsoft\Svchost.exe
    • %Windows%\IME\Crypt\Svchost.exe
    • %Windows%\IME\Crypt\Spoolsv.exe
    • %Windows%\IME\Daps\Svchost.exe
    • %System%\SysprepThemes\spoolsv.exe
    • %Windows%\SysprepThemes\Microsoft\svchost.exe
    • %Windows%\SysprepThemes\Microsoft\spoolsv.exe
    • %System%\SecureBootThemes\spoolsv.exe
    • %Windows%\SecureBootThemes\Microsoft\svchost.exe
    • %Windows%\SecureBootThemes\Microsoft\spoolsv.exe
    • %System%\SecUpdateHost.exe
    • %System%\ServicesHost.exe
    • %System%\WUDHostServices.exe
    • %System%\TrustedHostServices.exe
    • %Windows%\SpeechsTracing\spoolsv.exe
    • %System%\TasksHostServices.exe
    • %Windows%\SpeechsTracing\Microsoft\svchost.exe
    • %Windows%\SpeechsTracing\Microsoft\spoolsv.exe
    • %Windows%\AppDiagnostics\wininit.exe
    • %Windows%\AppDiagnostics\svchost.exe
    • %Windows%\AppDiagnostics\spoolsv.exe
    • %System%\WUDFHostex.exe
    • %System%\TrustedHostex.exe
  • It deletes older versions of its component file:
    • %System%\settings7283.dat
    • %System%\dnsclientprovider_userdata.mof
    • %System%\D0T73Z
    • %System%\NrsDataCache.tlb
    • %System%\ProximityUntilCache32.tlb
    • %System%\MsraReportDataCache32.tlb
    • %System%\EnrollCertXaml.dll
    • %System%\HalPluginsServices.dll
    • %System%\MarsTraceDiagnostics.xml
    • %System%\ExtractionHost.tlb
  • It deletes the following folders where the older versions of EternalBlue/DoublePulsar may be located:
    • %Windows%\IME\Microsoft\
    • %Windows%\IME\Crypt\
    • %Windows%\IME\Daps\
    • %System%\SysprepThemes\
    • %Windows%\SysprepThemes\Microsoft\
    • %System%\SecureBootThemes\
    • %Windows%\SecureBootThemes\Microsoft\
    • %Windows%\SpeechsTracing\
    • %Windows%\SpeechsTracing\Microsoft\
    • %Windows%\AppDiagnostics\
  • Drops the following component files that is used for the malware's EternalBlue/DoublePulsar Exploitation:
    • %Windows%\NetworkDistribution\process1.txt <- connection logs
    • %Windows%\NetworkDistribution\process2.txt <- connection logs
    • %Windows%\NetworkDistribution\svchost.xml <- config file {details of the targeted machine.}
    • %Windows%\NetworkDistribution\x86.dll
    • %Windows%\NetworkDistribution\x64.dll
    • %Windows%\NetworkDistribution\Diagnostics.txt
    • %Windows%\NetworkDistribution\Eternalblue-2.2.0.fb
    • %Windows%\NetworkDistribution\Eternalchampion-2.0.0.fb
    • %Windows%\NetworkDistribution\_pytrch.pyd
    • %Windows%\NetworkDistribution\adfw-2.dll
    • %Windows%\NetworkDistribution\adfw.dll
    • %Windows%\NetworkDistribution\cnli-0.dll
    • %Windows%\NetworkDistribution\cnli-1.dll
    • %Windows%\NetworkDistribution\coli-0.dll
    • %Windows%\NetworkDistribution\crli-0.dll
    • %Windows%\NetworkDistribution\dmgd-1.dll
    • %Windows%\NetworkDistribution\dmgd-4.dll
    • %Windows%\NetworkDistribution\esco-0.dll
    • %Windows%\NetworkDistribution\etch-0.dll
    • %Windows%\NetworkDistribution\etchCore-0.x64.dll
    • %Windows%\NetworkDistribution\etchCore-0.x86.dll
    • %Windows%\NetworkDistribution\eteb-2.dll
    • %Windows%\NetworkDistribution\etebCore-2.x64.dll
    • %Windows%\NetworkDistribution\etebCore-2.x86.dll
    • %Windows%\NetworkDistribution\exma-1.dll
    • %Windows%\NetworkDistribution\exma.dll
    • %Windows%\NetworkDistribution\iconv.dll
    • %Windows%\NetworkDistribution\libcurl.dll
    • %Windows%\NetworkDistribution\libeay32.dll
    • %Windows%\NetworkDistribution\libiconv-2.dll
    • %Windows%\NetworkDistribution\libxml2.dll
    • %Windows%\NetworkDistribution\out.dll
    • %Windows%\NetworkDistribution\pcla-0.dll
    • %Windows%\NetworkDistribution\pcre-0.dll
    • %Windows%\NetworkDistribution\pcrecpp-0.dll
    • %Windows%\NetworkDistribution\pcreposix-0.dll
    • %Windows%\NetworkDistribution\posh-0.dll
    • %Windows%\NetworkDistribution\posh.dll
    • %Windows%\NetworkDistribution\pytrch.py
    • %Windows%\NetworkDistribution\pytrch.pyc
    • %Windows%\NetworkDistribution\riar-2.dll
    • %Windows%\NetworkDistribution\riar.dll
    • %Windows%\NetworkDistribution\spoolsv.xml
    • %Windows%\NetworkDistribution\ssleay32.dll
    • %Windows%\NetworkDistribution\svchost.xml
    • %Windows%\NetworkDistribution\tibe-1.dll
    • %Windows%\NetworkDistribution\tibe-2.dll
    • %Windows%\NetworkDistribution\tibe.dll
    • %Windows%\NetworkDistribution\trch-0.dll
    • %Windows%\NetworkDistribution\trch-1.dll
    • %Windows%\NetworkDistribution\trch.dll
    • %Windows%\NetworkDistribution\trfo-0.dll
    • %Windows%\NetworkDistribution\trfo-2.dll
    • %Windows%\NetworkDistribution\trfo.dll
    • %Windows%\NetworkDistribution\tucl-1.dll
    • %Windows%\NetworkDistribution\tucl.dll
    • %Windows%\NetworkDistribution\ucl.dll
    • %Windows%\NetworkDistribution\x64.dll
    • %Windows%\NetworkDistribution\x86.dll
    • %Windows%\NetworkDistribution\xdvl-0.dll
    • %Windows%\NetworkDistribution\zibe.dll
    • %Windows%\NetworkDistribution\zlib1.dll
  • It executes the following set of commands:
    • schtasks.exe /End /TN "\Microsoft\Windows\UPnP\TPMangerAgentTask" <- Terminates the scheduled task
    • schtasks.exe /Delete /TN "\Microsoft\Windows\UPnP\TPMangerAgentTask" /F <- Deletes the scheduled task
    • schtasks.exe /Delete /TN "\Microsoft\Windows\Tcpip\TcpipReportingServices" /F<- Deletes the scheduled task
    • schtasks.exe /Delete /TN "\Microsoft\Windows\UPnP\UPnPHostServices" /F<- Deletes the scheduled task
    • schtasks.exe /Delete /TN "\Microsoft\Windows\Time Synchronization\Tpm-Optimize-Service" /F<- Deletes the scheduled task

  SOLUTION

Minimum Scan Engine:

9.850

FIRST VSAPI PATTERN FILE:

15.156.04

FIRST VSAPI PATTERN DATE:

06 Jun 2019

VSAPI OPR PATTERN File:

15.157.00

VSAPI OPR PATTERN Date:

07 Jun 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

Restart in Safe Mode

[ Learn More ]

Step 4

Identify and terminate files detected as Trojan.Win64.VOOLS.AH

[ 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 5

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 NT\CurrentVersion\NetworkPlatform\Location Awareness
    • LastBackup = {Hex Values}

Step 6

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%\NetworkDistribution\process1.txt <- connection logs
  • %Windows%\NetworkDistribution\svchost.xml <- config file {details of the targeted machine.}
  • %Windows%\NetworkDistribution\x86.dll
  • %Windows%\NetworkDistribution\x64.dll
  • %Windows%\NetworkDistribution\Diagnostics.txt
  • %Windows%\NetworkDistribution\Eternalblue-2.2.0.fb
  • %Windows%\NetworkDistribution\Eternalchampion-2.0.0.fb
  • %Windows%\NetworkDistribution\_pytrch.pyd
  • %Windows%\NetworkDistribution\adfw-2.dll
  • %Windows%\NetworkDistribution\adfw.dll
  • %Windows%\NetworkDistribution\cnli-0.dll
  • %Windows%\NetworkDistribution\cnli-1.dll
  • %Windows%\NetworkDistribution\coli-0.dll
  • %Windows%\NetworkDistribution\crli-0.dll
  • %Windows%\NetworkDistribution\dmgd-1.dll
  • %Windows%\NetworkDistribution\dmgd-4.dll
  • %Windows%\NetworkDistribution\esco-0.dll
  • %Windows%\NetworkDistribution\etch-0.dll
  • %Windows%\NetworkDistribution\etchCore-0.x64.dll
  • %Windows%\NetworkDistribution\etchCore-0.x86.dll
  • %Windows%\NetworkDistribution\eteb-2.dll
  • %Windows%\NetworkDistribution\etebCore-2.x64.dll
  • %Windows%\NetworkDistribution\etebCore-2.x86.dll
  • %Windows%\NetworkDistribution\exma-1.dll
  • %Windows%\NetworkDistribution\exma.dll
  • %Windows%\NetworkDistribution\iconv.dll
  • %Windows%\NetworkDistribution\libcurl.dll
  • %Windows%\NetworkDistribution\libeay32.dll
  • %Windows%\NetworkDistribution\libiconv-2.dll
  • %Windows%\NetworkDistribution\libxml2.dll
  • %Windows%\NetworkDistribution\out.dll
  • %Windows%\NetworkDistribution\pcla-0.dll
  • %Windows%\NetworkDistribution\pcre-0.dll
  • %Windows%\NetworkDistribution\pcrecpp-0.dll
  • %Windows%\NetworkDistribution\pcreposix-0.dll
  • %Windows%\NetworkDistribution\posh-0.dll
  • %Windows%\NetworkDistribution\posh.dll
  • %Windows%\NetworkDistribution\pytrch.py
  • %Windows%\NetworkDistribution\pytrch.pyc
  • %Windows%\NetworkDistribution\riar-2.dll
  • %Windows%\NetworkDistribution\riar.dll
  • %Windows%\NetworkDistribution\spoolsv.xml
  • %Windows%\NetworkDistribution\ssleay32.dll
  • %Windows%\NetworkDistribution\svchost.xml
  • %Windows%\NetworkDistribution\tibe-1.dll
  • %Windows%\NetworkDistribution\tibe-2.dll
  • %Windows%\NetworkDistribution\tibe.dll
  • %Windows%\NetworkDistribution\trch-0.dll
  • %Windows%\NetworkDistribution\trch-1.dll
  • %Windows%\NetworkDistribution\trch.dll
  • %Windows%\NetworkDistribution\trfo-0.dll
  • %Windows%\NetworkDistribution\trfo-2.dll
  • %Windows%\NetworkDistribution\trfo.dll
  • %Windows%\NetworkDistribution\tucl-1.dll
  • %Windows%\NetworkDistribution\tucl.dll
  • %Windows%\NetworkDistribution\ucl.dll
  • %Windows%\NetworkDistribution\x64.dll
  • %Windows%\NetworkDistribution\x86.dll
  • %Windows%\NetworkDistribution\xdvl-0.dll
  • %Windows%\NetworkDistribution\zibe.dll
  • %Windows%\NetworkDistribution\zlib1.dll
  • %System%\dllhostex.exe
  • %Windows%\NetworkDistribution\Diagnosis.txt
  • %System%\rdpwvq.tlb

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.
  • %Windows%\NetworkDistribution

Step 8

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

Step 9

Download and apply these security patches Refrain from using these products until the appropriate patches have been installed. Trend Micro advises users to download critical patches upon release by vendors. Microsoft Windows SMB Server (MS17-010) Vulnerability

Step 10

Scan your computer with your Trend Micro product to delete files detected as Trojan.Win64.VOOLS.AH. 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:


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