Arrival Details
This Potentially Unwanted Application 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 Potentially Unwanted Application drops the following component file(s):
- %User Temp%\{8 Random Characters}.sys
(Note: %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).)
Autostart Technique
This Potentially Unwanted Application 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\ControlSet001\
services\{8 Random Characters}
Other System Modifications
This Potentially Unwanted Application deletes the following files:
- %User Temp%\{8 Random Characters}.sys
(Note: %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).)
It adds the following registry entries as part of its installation routine:
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
services\{8 Random Characters}
Type = 1
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
services\{8 Random Characters}
ErrorControl = 1
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
services\{8 Random Characters}
Start = 3
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
services\{8 Random Characters}
ImagePath = \??\%User Temp%\{8 Random Characters}.sys
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
services\{8 Random Characters}
Group = Base
Information Theft
This Potentially Unwanted Application gathers the following data:
- List of Drives
- Computer Name
- Running Processes
- Process Modules
- Running Services
- Computer Files
- Disk Sectors
- System Registries
- Clipboard Data
Other Details
This Potentially Unwanted Application does the following:
- It loads the dropped file as a driver
- %User Temp%\{8 Random Characters}.sys
- It displays the following image

- It displays and can delete, copy, and kill files and folders
- It displays and can create and kill system processes
- It displays process modules
- It can edit, disable and delete services
- It displays and can edit system registry data
- It can export registry data and save it in a file
- It can execute shell commands
- It can restore SSDT tables
- It can restore the Master Boot Record (MBR)
- The tool scans for the following:
- Hidden Processes
- Hidden Threads
- Hidden Modules
- Hidden Services
- Hidden Files
- Hidden Disk Sectors (MBR)
- Hidden Alternate Data Streams
- Hidden Registry Keys
- Drivers Hooking SSDT
- Drivers Hooking IDT
- Drivers Hooking IRP calls
- Inline Hooks
- It displays process libraries and threads
- It can restart the machine
- This tool has been abused by other malware to terminate processes relating to security-related software via its -killfile option
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
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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 4
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_LOCAL_MACHINE\SYSTEM\ControlSet001\services\{8 Random Characters}
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\services\{8 Random Characters}
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\services\{8 Random Characters}
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\services\{8 Random Characters}
- ImagePath = \??\%User Temp%\{8 Random Characters}.sys
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\services\{8 Random Characters}
To delete the registry value this malware/grayware created:
- Open Registry Editor.
» For Windows 7 and Server 2008 (R2) users, click the Start button, type regedit in the Search input field then press Enter.
» For Windows 8, 8.1, 10, and 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>SYSTEM>ControlSet001>services>{8 Random Characters} - In the right panel, locate and delete the entry:
Type = 1 - Again In the right panel, locate and delete the entry:
ErrorControl = 1 - Again In the right panel, locate and delete the entry:
Start = 3 - Again In the right panel, locate and delete the entry:
ImagePath = \??\%User Temp%\{8 Random Characters}.sys - Again In the right panel, locate and delete the entry:
Group = Base - Close Registry Editor.
Step 5
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.
- HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\services\{8 Random Characters}
To delete registry keys this malware/grayware created:
- Open Registry Editor. To do this:
» For Windows 7 and Server 2008 (R2) users, click the Start button, type regedit in the Search input field then press Enter.
» For Windows 8, 8.1, 10, and 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. - HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\services\{8 Random Characters}
- Close Registry Editor.
Step 6
Scan your computer with your Trend Micro product to delete files detected as PUA.Win32.GMER.A. 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:
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