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 the following copies of itself into the affected system:
- %application data%\{malware file name}.js
It adds the following processes:
- "%System%\wscript.exe" "%Application Data%\187d7780d42792aa825d203b3724058bf76b08ee.js"
- wscript.exe "%Application Data%\187d7780d42792aa825d203b3724058bf76b08ee.js"
(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Roaming on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)
Autostart Technique
This Worm adds the following registry entries to enable its automatic execution at every system startup:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
187d7780d42792aa825d203b3724058bf76b08ee = "{random characters}"
Other System Modifications
This Worm adds the following registry keys:
HKEY_LOCAL_MACHINE\software\187d7780d42792aa825d203b3724058bf76b08ee
It adds the following registry entries:
HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\
187d7780d42792aa825d203b3724058bf76b08ee
(Default) = "false - 8/7/2019"
HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\
Microsoft\Windows\CurrentVersion\
Run
187d7780d42792aa825d203b3724058bf76b08ee = "{random characters}"
Dropping Routine
This Worm drops the following files:
- %user startup%\{malware file name}.js
This report is generated via an automated analysis system.
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
Restart in Safe Mode
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To restart in Safe Mode:
• For Windows 7 and Windows Server 2008 (R2) users
- Restart your computer.
- Press F8 after the Power-On Self Test (POST) routine is done. If the Advanced Boot Options menu does not appear, try restarting and then pressing F8 several times after the POST screen is displayed.
- On the Advanced Boot Options menu, use the arrow keys to select the Safe Mode option, and then press Enter.
• For Windows 8, Windows 8.1, and Windows Server 2012 users
- Access the Charms bar by moving your mouse pointer to the upper right corner of the screen.
- Move your mouse pointer down and click Settings>Change your PC Settings.
- In the left panel, click General.
- In the right panel, scroll down to the bottom to find the Advanced startup section, then click the Restart now button and wait for the system to restart.
- In the Advanced Startup menu, click Troubleshoot>Advanced Options>Startup Settings>Restart and wait for the system to restart.
- In the Startup Settings menu, press 4 to enable safe mode.
• For Windows 10 users
- Press Windows logo key + I on your keyboard to open Settings. If that doesn't work, select the Start button, then select Settings.
- Select Update & Security > Recovery.
- Under Advanced startup, select Restart now.
- After your PC restarts to the Choose an option screen, select Troubleshoot > Advcanced options > Startup settings > Restart.
- After your PC restarts, you'll see a list og options. Select 4 or press F4 to start your PC in Safe Mode.
Step 3
Identify and terminate files detected as Worm.JS.NEMUCOD.WEALSX
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- 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.
- 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.
- If the detected file is not displayed in either Windows Task Manager or Process Explorer, continue doing the next steps.
To terminate the malware/grayware/spyware process:
- Scan your computer with your Trend Micro product and take note of the name of the malware/grayware/spyware detected.
- Open Windows Task Manager. To do this, press CTRL+SHIFT+ESC.
- View the list of all running programs. To do this:
• For Windows 7 and Server 2008 (R2) users, click the Processes tab.
• For Windows 8, 8.1, 10, and Server 2012 (R2) users, click the Details tab. - In the list of running programs, locate a malware/grayware/spyware file detected earlier.
- Select the detected files, then press either the End Task or the End Process button, depending on the version of Windows you are using.
- Do the same for the remaining detected malware/grayware/spyware files in the list of running programs.
- To check if the malware/grayware/spyware process has been terminated, close Task Manager, and then open it again.
- Close Task Manager.
Step 4
Delete this registry key
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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
- 187d7780d42792aa825d203b3724058bf76b08ee
To delete the registry key this malware/grayware created:
- Open Registry Editor.
» For Windows 7 and Windows Server 2008 (R2) users, click the Start button, type regedit in the Search input field then press Enter.
» For Windows 8, Windows 8.1, Windows 10, and Windows Server 2012 (R2) users, right-click on the lower left corner of the screen, click Run, type regedit in the text box provided, and then press Enter. - In the left panel, double-click the following:
HKEY_LOCAL_MACHINE>software - Still in the left panel, locate and delete the key:
187d7780d42792aa825d203b3724058bf76b08ee - Close Registry Editor.
Step 5
Delete this registry value
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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\Run
- 187d7780d42792aa825d203b3724058bf76b08ee = "{random characters}"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\187d7780d42792aa825d203b3724058bf76b08ee
- (Default) = "false - 8/7/2019"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\Windows\CurrentVersion\Run
- 187d7780d42792aa825d203b3724058bf76b08ee = "{random characters}"
To delete the registry value this malware/grayware created:
- Open Registry Editor.
» For Windows 7 and Windows Server 2008 (R2) users, click the Start button, type regedit in the Search input field then press Enter.
» For Windows 8, Windows 8.1, Windows 10, and Windows Server 2012 (R2) users, right-click on the lower-left corner of the screen, click Run, type regedit in the text box provided, and then press Enter. - In the left panel, double-click the following:
HKEY_CURRENT_USER>Software>Microsoft>Windows>CurrentVersion>Run - In the right panel, locate and delete the entry:
187d7780d42792aa825d203b3724058bf76b08ee = "{random characters}" - In the left panel, double-click the following:
HKEY_LOCAL_MACHINE>SOFTWARE>Wow6432Node>187d7780d42792aa825d203b3724058bf76b08ee - In the right panel, locate and delete the entry:
(Default) = "false - 8/7/2019" - In the left panel, double-click the following:
HKEY_LOCAL_MACHINE>SOFTWARE>Wow6432Node>Microsoft>Windows>CurrentVersion>Run - In the right panel, locate and delete the entry:
187d7780d42792aa825d203b3724058bf76b08ee = "{random characters}" - Close Registry Editor.
Step 6
Search and delete this file
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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.
- %user startup%\{malware file name}.js
To manually delete a malware/grayware file from an affected system:
•For Windows 7, Windows Server 2008 (R2), Windows 8, Windows 8.1, Windows 10, and Windows Server 2012 (R2):
- Open a Windows Explorer window.
- For Windows 7 and Server 2008 (R2) users, click Start>Computer.
- For Windows 8, 8.1, 10, and Server 2012 (R2) users, right-click on the lower-left corner of the screen,then click File Explorer.
- In the Search Computer/This PC input box, type:
- %user startup%\{malware file name}.js
- Once located, select the file then press SHIFT+DELETE to delete it.
*Note: Read the following Microsoft page if these steps do not work on Windows 7 and Windows Server 2008 (R2).
Step 7
Restart in normal mode and scan your computer with your Trend Micro product for files detected as Worm.JS.NEMUCOD.WEALSX. 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.
