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BKDR_PLUGX.DUKQU

April 10, 2020
 ALIASES:

Trojan.Gen.2 (Symantec); Trojan.Win32.Agentb.jjse (Kaspersky); Trojan.Win32.Generic!BT (Sunbelt)

 PLATFORM:

Windows

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

  • Threat Type: Backdoor

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW


This Backdoor 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:

1,302,280 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

10 Apr 2020

Arrival Details

This Backdoor 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 Backdoor adds the following processes:

  • rundll32 "%Program Files%\COMMON~1\MICROS~1\TextConv\NSLS.dll",Main
  • %Windows%\Microsoft.NET\Framework\v4.0.30319\mscorsvw.exe
  • %System%\svchost.exe -k LocalServiceAndNoImpersonation
  • %Windows%\Microsoft.NET\Framework64\v4.0.30319\mscorsvw.exe
  • %System%\sppsvc.exe
  • "%System Root%\Program Files\Windows Media Player\wmpnetwk.exe"
  • %System%\svchost.exe -k WerSvcGroup
  • %System%\svchost.exe -k netsvcs
  • %System%\dllhost.exe 209 2680
  • %System%\WerFault.exe -u -p 2540 -s 1236
  • %System%\WerFault.exe -u -p 2156 -s 212
  • %System%\WerFault.exe -u -p 2068 -s 204
  • %System%\WerFault.exe -u -p 2068 -s 208
  • %System%\WerFault.exe -u -p 680 -s 1532
  • %System%\WerFault.exe -u -p 680 -s 1536
  • %System%\WerFault.exe -u -p 2728 -s 180
  • %System%\WerFault.exe -u -p 2728 -s 176

(Note: %Program Files% is the default Program Files folder, usually C:\Program Files in Windows 2000(32-bit), Server 2003(32-bit), XP, Vista(64-bit), 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit) , or C:\Program Files (x86) in Windows XP(64-bit), Vista(64-bit), 7(64-bit), 8(64-bit), 8.1(64-bit), 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.. %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.. %System Root% is the Windows root folder, where it usually is C:\ on all Windows operating system versions.)

It creates the following folders:

  • %Windows%\ServiceProfiles\NetworkService\AppData\Local\Microsoft

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

Autostart Technique

This Backdoor registers itself as a system service to ensure its automatic execution at every system startup by adding the following registry entries:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\NSLS
ImagePath = "rundll32 %Program Files%\COMMON~1\MICROS~1\TextConv\NSLS.dll,Main"

Other System Modifications

This Backdoor deletes the following files:

  • {malware file path and name}

It adds the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\
Microsoft\Windows\CurrentVersion\
Uninstall
NSLS = "{malware file path and name}"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
services\NSLS
Description = "@%SystemRoot%\system32\nsisvc.dll,-201"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
TFAS
CLSID = "7\x007\x009\x004\x00D\x003\x000\x00A\x00E\x00A\x00F\x00D\x006\x005\x00B\x00E\x00\x00\x00"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\NetworkList\
Nla\Cache\Intranet
{89BCDCB3-5725-45A2-94AB-2D6B641209B0} = "\x00PV\xbc\x0f\x1d"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Security Center
cval = "0"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\NSLS
DisplayName = "Network Store Location Service"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\NSLS
Start = "SERVICE_AUTO_START"

It deletes the following registry keys:

HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\
Microsoft\Windows\CurrentVersion\
Uninstall\NSLS

Dropping Routine

This Backdoor drops the following files:

  • %All Users Profile%\Microsoft\Windows\DRM\v3ks.sec
  • %All Users Profile%\Microsoft\Windows\DRM\drmstore.hds
  • %Windows%\AppPatch\msimain17.sdb
  • %AppDataLocal%\Microsoft\Media Player\CurrentDatabase_372.wmdb
  • %Program Files%\Common Files\Microsoft Shared\TextConv\NSLS.dll

(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). . %Windows% is the Windows folder, where it usually is C:\Windows on all Windows operating system versions.. %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).. %Program Files% is the default Program Files folder, usually C:\Program Files in Windows 2000(32-bit), Server 2003(32-bit), XP, Vista(64-bit), 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit) , or C:\Program Files (x86) in Windows XP(64-bit), Vista(64-bit), 7(64-bit), 8(64-bit), 8.1(64-bit), 2008(64-bit), 2012(64-bit) and 10(64-bit).)

Other Details

This Backdoor connects to the following possibly malicious URL:

  • http://www.{BLOCKED}oft.com/pki/certs/MicRooCerAut_2010-06-23.crt
  • http://news.{BLOCKED}softservice.net

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 BKDR_PLUGX.DUKQU

[ 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\Wow6432Node\Microsoft\Windows\CurrentVersion\Uninstall
    • NSLS = "{malware file path and name}"
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\NSLS
    • Description = "@%SystemRoot%\system32\nsisvc.dll,-201"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\TFAS
    • CLSID = "7\x007\x009\x004\x00D\x003\x000\x00A\x00E\x00A\x00F\x00D\x006\x005\x00B\x00E\x00\x00\x00"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\NetworkList\Nla\Cache\Intranet
    • {89BCDCB3-5725-45A2-94AB-2D6B641209B0} = "\x00PV\xbc\x0f\x1d"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Security Center
    • cval = "0"
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\NSLS
    • DisplayName = "Network Store Location Service"
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\NSLS
    • Start = "SERVICE_AUTO_START"

Step 4

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
  • %Windows%\AppPatch\msimain17.sdb
  • %AppDataLocal%\Microsoft\Media Player\CurrentDatabase_372.wmdb
  • %Program Files%\Common Files\Microsoft Shared\TextConv\NSLS.dll

Step 5

Search and delete this folder

[ 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%\ServiceProfiles\NetworkService\AppData\Local\Microsoft

Step 6

Scan your computer with your Trend Micro product to delete files detected as BKDR_PLUGX.DUKQU. 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.

  • {malware file path and name}

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\Wow6432Node\Microsoft\Windows\CurrentVersion\Uninstall
    • NSLS


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