VBS_NEMUCOD.ELDSAUY
VBS/Kryptik.HC (ESET-NOD32)
Windows
Threat Type: Worm
Destructiveness: No
Encrypted:
In the wild: Yes
OVERVIEW
This Worm arrives as an attachment to email messages spammed by other malware/grayware or malicious users. It arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.
However, as of this writing, the said sites are inaccessible.
TECHNICAL DETAILS
Arrival Details
This Worm arrives as an attachment to email messages spammed by other malware/grayware or malicious users.
It 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:
- %User Temp%\{Malware Filename and Extension}
(Note: %User Temp% is the user's temporary folder, where it usually is C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local\Temp on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.)
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
HAR1EEPZKW = “%User Temp%\{Malware Filename and Extension}”
It drops the following file(s) in the Windows Startup folder to enable its automatic execution at every system startup:
- %User Startup%\{Malware Filename and Extension}
(Note: %User Startup% is the current user's Startup folder, which is usually C:\Documents and Settings\{user}\Start Menu\Programs\Startup on Windows 2000 and XP, and C:\Documents and Settings\{User name}\Start Menu\Programs\Startup on Windows Vista, 7, and 8.)
Propagation
This Worm drops copies of itself in the following drives:
- {Removable Drive Letter}:\{Malware Filename and Extension}
Other Details
This Worm connects to the following possibly malicious URL:
- http://microstar2014.myftp.biz:7776/Vre
It does the following:
- This malware creates a scheduled task for its dropped copy:
- Skype = “%User Temp%\{Malware Filename and Extension}”
(Note: %User Temp% is the user's temporary folder, where it usually is C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local\Temp on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.)
However, as of this writing, the said sites are inaccessible.
SOLUTION
Step 1
Before doing any scans, Windows XP, Windows Vista, and Windows 7 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_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
- HAR1EEPZKW = “%User Temp%\{Malware Filename and Extension}”
- HAR1EEPZKW = “%User Temp%\{Malware Filename and Extension}”
Step 5
Delete the Scheduled Tasks added by this malware/grayware
To delete the added Scheduled Task file:
For Windows 2000, Windows XP, and Windows Server 2003:
- Open the Windows Scheduled Tasks. To do this, click Start>Programs>Accessories>System Tools>Scheduled Tasks.
- Double-click on a .JOB file.
- Check if the malware path and file name exists in the .JOB file. To do this, check the value in the Run field.
- If found, select the .JOB file then press SHIFT+DELETE to permanently delete the file.
- Repeat the steps above for the remaining .JOB files.
For Windows Vista, Windows 7, Windows Server 2008, Windows 8, Windows 8.1, and Windows Server 2012:
- Open the Windows Task Scheduler. To do this:
• On Windows Vista, Windows 7, and Windows Server 2008, click Start, type taskschd.msc in the Search input field, then press Enter.
• On Windows 8, Windows 8.1, and Windows Server 2012, right-click on the lower left corner of the screen, click Run, type taskschd.msc, then press Enter. - In the left panel of the Task Scheduler Window, click Task Scheduler Library.
- In the upper-middle panel, click a Task.
- In the lower middle panel, click the Actions tab
- Check if the malware path and file name exists in the task. To do this, check the value in the Details column under the Actions tab.
- If found, select the task and press DELETE and click Yes to delete the task.
- Repeat the steps above for the remaining tasks.
Step 6
Restart in normal mode and scan your computer with your Trend Micro product for files detected as VBS_NEMUCOD.ELDSAUY. 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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