Virus.MSIL.MAZEFECT.A
Trojan:Win32/Lunam (MICROSOFT), HEUR:Trojan.MSIL.Injects.gen (KASPERSKY)
Windows
Threat Type: Virus
Destructiveness: No
Encrypted: Yes
In the wild: Yes
OVERVIEW
Downloaded from the Internet, Dropped by other malware
This Virus arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.
It adds infection markers to files.
TECHNICAL DETAILS
533,658 bytes
EXE
Yes
17 May 2023
Encrypts files, Drops files
Arrival Details
This Virus 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 Virus drops the following files:
- %User Temp%\{15 random alphanumeric characters}.exe → original copy of any infected file
(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 drops the following copies of itself into the affected system:
- %User Temp%\CTS.exe
- %Windows%\CTS.exe
(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).. %Windows% is the Windows folder, where it usually is C:\Windows on all Windows operating system versions.)
It adds the following processes:
- %Temp%\{15 random alphanumeric character}.exe
- %Windows%\CTS.exe
(Note: %Temp% is the Windows temporary folder, where it usually is C:\Windows\Temp on all Windows operating system versions.. %Windows% is the Windows folder, where it usually is C:\Windows on all Windows operating system versions.)
It adds the following mutexes to ensure that only one of its copies runs at any one time:
- Global\3pc6RWOgectGTFqCowxjeGy3XIGPtLwNrsr2zDctYD4hAU5pj4GW7rm8gHrHyTB6
Autostart Technique
This Virus adds the following registry entries to enable its automatic execution at every system startup:
HKEY_LOCAL_MACHINE\Software\Microsoft\
Windows\CurrentVersion\Run
CTS = %Windows%\CTS.exe
HKEY_CURRENT_USER\SOFTWARE\Microsoft\
CurrentVersion\Run
CTS = %User Temp%\CTS.exe
File Infection
This Virus infects the following files:
- %User Profile%\{Filename}.exe
- {Network / Remote Drive}\{Filename}.exe
- {Removable Drive}\{Filename}.exe
(Note: %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name} on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)
It infects the following file types:
- exe
It adds infection markers to files.
Other Details
This Virus does the following:
- It continuously monitors for .exe files to infect on removable and network / remote drives.
- It checks if the following virtual machine- or sandbox-related strings are present in the affected system:
- MALWARE
- S3 Trio32/64
- SAMPLE
- SANDBOX
- SCHMIDTI
- USER
- VirtualBox Graphics Adapter
- VIRUS
- VM Additions S3 Trio32/64
- VMWARE
- VMware SVGA II
- It checks if the following virtual machine- or sandbox-related window are present in the affected system:
- Afx:400000:0 → WinJail Sandbox
It checks if the following virtual machine or sandbox related module(s) is loaded in the affected system:
- SbieDLL.dll
It checks if the following virtual machine- or sandbox-related registry keys are present in the affected system:
HKEY_LOCAL_MACHINE\HARDWARE\DEVICEMAP\
Scsi\Scsi Port 0\Scsi Bus 0\
Target Id 0\Logical Unit Id 0
Identifier = VBOX
HKEY_LOCAL_MACHINE\HARDWARE\Description\
System
HKEY_LOCAL_MACHINE\HARDWARE\Description\
System
VideoBiosVersion = VIRTUALBOX
HKEY_LOCAL_MACHINE\SOFTWARE\Oracle\
VirtualBox Guest Additions
HKEY_LOCAL_MACHINE\HARDWARE\DEVICEMAP\
Scsi\Scsi Port 0\Scsi Bus 0\
Target Id 0\Logical Unit Id 0
Identifier = VMWARE
HKEY_LOCAL_MACHINE\SOFTWARE\VMware, Inc.\
VMware Tools
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Disk\Enum
0 = vmware
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Control\Class\4D36E968-E325-11CE-BFC1-08002BE10318\
0000
DriverDesc = VMWARE
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Control\Class\4D36E968-E325-11CE-BFC1-08002BE10318\
0000\Settings
Device Description = VMWARE
HKEY_LOCAL_MACHINE\SOFTWARE\VMware, Inc.\
VMware Tools
InstallPath = C:\PROGRAM FILES\VMWARE\VMWARE TOOLS\
HKEY_LOCAL_MACHINE\HARDWARE\DEVICEMAP\
Scsi\Scsi Port 0\Scsi Bus 0\
Target Id 0\Logical Unit Id 0
Identifier = QEMU
HKEY_LOCAL_MACHINE\HARDWARE\Description\
System
SystemBiosVersion = QEMU
It checks if the following virtual machine or sandbox related folder(s) or file(s) is present in the affected system:
- C:\file.exe
SOLUTION
9.800
18.460.04
22 May 2023
18.461.00
23 May 2023
Step 1
Trend Micro Predictive Machine Learning detects and blocks malware at the first sign of its existence, before it executes on your system. When enabled, your Trend Micro product detects this malware under the following machine learning name:
- PUA.Win32.TRX.XXPE50FFF068
Step 2
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 3
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 4
Restart in Safe Mode
Step 5
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\SOFTWARE\Microsoft\CurrentVersion\Run
- CTS = %Windows%\CTS.exe
- CTS = %Windows%\CTS.exe
- In HKEY_CURRENT_USER\SOFTWARE\Microsoft\CurrentVersion\Run
- CTS = %User Temp%\CTS.exe
- CTS = %User Temp%\CTS.exe
Step 6
Search and delete these files
- %Temp%\{15 random alphanumeric characters}.exe
- %Windows%\CTS.exe
- %User Temp%\CTS.exe
Step 7
Restart in normal mode and scan your computer with your Trend Micro product for files detected as Virus.MSIL.MAZEFECT.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 this Knowledge Base page for more information.
Did this description help? Tell us how we did.