BKDR_LUMINOSITY.B

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

It is injected into all running processes to remain memory resident.

It does not have any propagation routine.

It executes commands from a remote malicious user, effectively compromising the affected system.

It deletes the initially executed copy of itself.

Arrival Details

This backdoor 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 backdoor drops the following copies of itself into the affected system and executes them:

• %Application Data%\Microsoft\Credentials\upnpss.exe
• %System Root%\{random numbers 1}\svchost.exe
• %System%\clientmonitor.exe

(Note: %Application Data% is the Application Data folder, where it usually is C:\Documents and Settings\{user name}\Application Data on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Roaming 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.. %System Root% is the Windows root folder, where it usually is C:\ on all Windows operating system versions.. %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.)

It drops the following file(s)/component(s):

• %Application Data%\Microsoft\Credentials\lanmon.exe (watchdog) - also detected as BKDR_LUMINOSITY.B

(Note: %Application Data% is the Application Data folder, where it usually is C:\Documents and Settings\{user name}\Application Data on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Roaming 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.)

It adds the following processes:

• svchost.exe
• AppLaunch.exe
• vbc.ex
• RegAsm.exe
• RegSvcs.exe

It creates the following folders:

• {installation directory}\{random numbers 1}
• {installation directory}\{random numbers 2}\{random numbers 3}
• {installation directory}\{random numbers 2}\{random numbers 4}
• {installation directory}\{random numbers 2}\{random numbers 5}

It is injected into all running processes to remain memory resident.

It terminates itself if it finds the following processes in the affected system's memory:

• sandboxierpcss.exe

Autostart Technique

This backdoor adds the following registry entries to enable its automatic execution at every system startup:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
ADOBE READER = ""{installation directory}\{random numbers 1}\svchost.exe" -a /a"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Winlogon
Userinit = "userinit.exe,"%System%\clientmonitor.exe""

It creates the following registry entries to enable automatic execution of dropped component at every system startup:

HKEY_CURRENT_USER\Software\Microsoft\
Windows NT\CurrentVersion\Windows
Load = "cmd /c %Application Data%\Microsoft\Credentials\lanmon.exe"

Propagation

This backdoor does not have any propagation routine.

Backdoor Routine

This backdoor executes the following commands from a remote malicious user:

• Download and execute arbitrary files
• Download and execute custom Crypto Miner
• Download custom password recovery tool
• Search for files
• Perform DDOS
• Modify HOSTS file to redirect hosts/URLs
• Visit arbitrary websites (browser can be hidden and have muted audio)
• Seed torrent
• Update itself
• Update backup C&C
• Remote Desktop Control
• Remote shell
• Record audio using system's microphone
• Control Webcam
• Uninstall itself
• Execute/Terminate/Disable Task Manager
• Execute/Terminate/Disable Command Prompt
• Execute/Terminate/Disable Registry Editor
• Hide/Show Taskbar
• Hide/Show Desktop
• Open/Close CD-ROM door
• Swap/Reset Mouse
• Delete Restore points
• Enable/Disable input
• Log off
• Hibernate
• Shutdown system
• Perform network speed test
• Send the followng information:
  
  • CPU information
  • GPU information
  • RAM information
  • Security information
  • Uptime
  • Active Windows
  • Current malware file location
  • Full OS version
  • Keystroke logs
  • Stored passwords
  
  

It connects to the following URL(s) to send and receive commands from a remote malicious user:

• chuksthedon.{BLOCKED}s.org:1177

Other Details

This backdoor deletes the initially executed copy of itself

NOTES:

The variable {installation directory} depends on the affected system's operating system:

• %System Root% - for Windows XP and older
• %ProgramData% - for Windows Vista and recent

The variables {random numbers 3}, {random numbers 4}, and {random numbers 5} are consecutive numbers.

It proactively blocks anti-malware services by querying the installed anti-malware/firewall product in the system. Once an anti-malware/firewall is found, it terminates the corresponding anti-malware service/process.

It checks for the presence of Avast Antivirus by searching for snxhk.dll module. It puts itself in Sleep mode if this malware finds the said module.

It terminates itself if any of the following driver description is found:

• virtualbox graphics adapter
• vmware svga ii
• vm additions s3 trio32/64