Worm.Win32.AUTORUN.NIAR
Worm:Win32/Nuj.B (MICROSOFT)
Windows
![](/vinfo/imgFiles/legend.jpg)
Threat Type: Worm
Destructiveness: No
Encrypted: Yes
In the wild: Yes
OVERVIEW
This Worm arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.
As of this writing, the said sites are inaccessible.
TECHNICAL DETAILS
Arrival Details
This Worm 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 Worm drops a copy of itself in the following folders using different file names:
- {Available Drive}\SystemVolumeInformation\System.exe
It drops the following copies of itself into the affected system and executes them:
- %System%\taskmg.exe
(Note: %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.)
It drops the following files:
- %System%\sys1.ini ← created by svhist.exe
- %System%\about.txt
- %System%\julysoft.exe ← later renamed to cnfmon.exe
- {Available Drive}\Autorun.inf ← executes dropped copy in {Available Drive}\SystemVolumeInformation\System.exe
(Note: %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.)
It drops and executes the following files:
- %System%\spool.exe ← detected as Worm.Win32.AUTORUN.NIAR, adds and starts WindowsDriver service, ensures that taskmg.exe is running
- %System%\svhist.exe ← detected as Worm.Win32.AUTORUN.NIAR, downloads julysoft.exe and renames it to cnfmon.exe, drops %System%\about.txt and %System%\sys1.ini
- %System%\cnfmon.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 mutexes to ensure that only one of its copies runs at any one time:
- julychina ← added by taskmg.exe
- shengjik ← added by svhist.exe
Other System Modifications
This Worm adds the following registry entries as part of its installation routine:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\WindowsDriver
DisplayName = WindowsDriver
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\WindowsDriver
ImagePath = %System%\spool.exe
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\WindowsDriver
Start = 2
It adds the following registry keys as part of its installation routine:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services
WindowsDriver =
Download Routine
This Worm connects to the following URL(s) to download its component file(s):
- http://{BLOCKED}ft.cn/data/data.html
It saves the files it downloads using the following names:
- %Temporay Internet Files%\Content.IE5\{8 Random Characters}\data[1].htm
As of this writing, the said sites are inaccessible.
Other Details
This Worm does the following:
- It adds and runs the following services:
- DisplayName: WindowsDriver
ImagePath: %System%\spool.exe
Start: 2
- DisplayName: WindowsDriver
(Note: %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.)
SOLUTION
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
Step 4
Delete this registry value
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\SYSTEM\CurrentControlSet\Services\WindowsDriver
- DisplayName = WindowsDriver
- DisplayName = WindowsDriver
- In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\WindowsDriver
- ImagePath = %System%\spool.exe
- ImagePath = %System%\spool.exe
- In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\WindowsDriver
- Start = 2
- Start = 2
Step 5
Delete this registry key
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. Before you could do this, you must restart in Safe Mode. For instructions on how to do this, you may refer to this page If the preceding step requires you to restart in safe mode, you may proceed to edit the system registry.
- In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services
- WindowsDriver
- WindowsDriver
Step 6
Disable this malware service
- WindowsDriver
Step 7
Search and delete this file
- %System%\taskmg.exe
- %System%\spool.exe
- %System%\svhist.exe
- %Temporay Internet Files%\Content.IE5\{8 Random Characters}\data[1].htm
- %System%\sys1.ini
- %System%\julysoft.exe
- %System%\cnfmon.exe
- %System%\about.txt
- {Available Drive}\Autorun.inf
- {Available Drive}\SystemVolumeInformation\System.exe
Step 8
Search and delete this folder
- {Available Drive}\SystemVolumeInformation
Step 9
Restart in normal mode and scan your computer with your Trend Micro product for files detected as Worm.Win32.AUTORUN.NIAR. 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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