Backdoor.MSIL.NANOCORE.TIAOODED

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

It gathers certain information on the affected computer.

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.

This malware arrives via the following means:

• Downloaded by Trojan.Win32.NANOCORE.IMGYAPA

Installation

This Backdoor drops the following file(s)/component(s):

• %Common Startup%\Chrome.js -> executes the malware
• %Common Startup%\Chrome.lnk -> executes the malware
• Admin Privilege:
  
  • %Program Files%\{String 1}{String 3}\{String 1}{String 2}.exe
• User Privilege:
  
  • %Application Data%\{GUID}\{String 1}{String 3}\{String 1}{String 2}.exe

(Note: %Common Startup% is the startup folder for all users, which is usually C:\Documents and Settings\All Users\Start Menu\Programs\Startup on Windows 2000, XP, and Server 2003, or C:\ProgramData\Microsoft\Windows\Start Menu\Programs\Startup on Windows Vista, 7, and 8.. %Program Files% is the default Program Files folder, usually C:\Program Files in Windows 2000(32-bit), Server 2003(32-bit), XP, Vista(64-bit), 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit) , or C:\Program Files (x86) in Windows XP(64-bit), Vista(64-bit), 7(64-bit), 8(64-bit), 8.1(64-bit), 2008(64-bit), 2012(64-bit) and 10(64-bit).. %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Roaming on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)

It creates the following folders:

• %Application Data%\{GUID}
• %Application Data%\{GUID}\PCI Service
• %Application Data%\{GUID}\Logs
• %Application Data%\{GUID}\Logs\{UserName}
• %Application Data%\Robocopy
• Admin Privilege:
  
  • %Program Files%\{String 1}{String 2}
• User Privilege:
  
  • %Application Data%\{String 1}{String 2}

(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Roaming on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).. %Program Files% is the default Program Files folder, usually C:\Program Files in Windows 2000(32-bit), Server 2003(32-bit), XP, Vista(64-bit), 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit) , or C:\Program Files (x86) in Windows XP(64-bit), Vista(64-bit), 7(64-bit), 8(64-bit), 8.1(64-bit), 2008(64-bit), 2012(64-bit) and 10(64-bit).)

Autostart Technique

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

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
{String 1}{String 3} = %Program Files%\{String 1}{String 3}\{String 1}{String 2}.exe → Admin Privilege

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
{String 1}{String 3} = %Application Data%\{GUID}\{String 1}{String 3}\{String 1}{String 2}.exe → User Privilege

Backdoor Routine

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

• Manage its backdoor file:
  
  • Update itself
  • Restart connection
  • Disconnect
  • Terminate itself
  • Uninstall itself
• System Control:
  
  • Restart machine
  • Shutdown machine
  • Lock machine
  • Browse files and folders
  • Task Manager
  • Edit registry
  • Remote console (Command Prompt)
  • Remote execute a file
  • Remote execute a script (Batch, HTML, VBS, Python, Java, PHP)
  • Remote control the machine
  • Remote control mouse
  • Recover browser passwords
  • Log Keystrokes
  • View the screen/webcam
  • Listen to audio/microphone
  • Send Messages / Chat with the malicious user
  • Swap/Unswap mouse buttons
  • Open/Close CD/DVD Tray

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

• {BLOCKED}.{BLOCKED}.0.1:9033
• {BLOCKED}.{BLOCKED}.{BLOCKED}.249:2066

Dropping Routine

This Backdoor drops the following files:

• %Application Data%\{GUID}\catalog.dat
• %Application Data%\{GUID}\run.dat
• %Application Data%\{GUID}\settings.bin
• %Application Data%\{GUID}\Logs\{user name}\KB_{Random numbers}.dat
• %Application Data%\{GUID}\task.dat
• %Application Data%\{GUID}\storage.dat

(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Roaming on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)

Information Theft

This Backdoor gathers the following information on the affected computer:

• Computer Name
• User Name
• CPU Usage
• Available and Free Memory
• Active Window Title
• Operating System Version
• System Type (32-bit or 64-bit)
• Malware Filename
• Installed Anti-Virus/Anti-Spyware

Other Details

This Backdoor does the following:

• String 1 can be any of the following:
  
  • dhcp
  • upnp
  • tcp
  • udp
  • saas
  • iss
  • smtp
  • dos
  • dpi
  • pci
  • scsi
  • wan
  • lan
  • nat
  • imap
  • nas
  • ntfs
  • wpa
  • dsl
  • agp
  • arp
  • ddp
  • dns
• String 2 can be any of the following:
  
  • ss
  • mon
  • Mgr
  • sv
  • svc
  • host
• String 3 can be any of the following:
  
  • Subsystem
  • Monitor
  • Manager
  • Service
  • Host
• It will drop %Common Startup%\Chrome.js once the following files are found on the affected computer:
  
  • C:\Program Files\AVAST Software\Avast\avastIU.exe
  • C:\Program Files (x86)\AVAST Software\Avast\avastIU.exe
  • C:\Program Files\AVG\Antivirus\AVGUI.exe
  • C:\Program Files (x86)\AVG\Antivirus\AVGUI.exe
• It will drop %Common Startup%\Chrome.lnk once the following directories are found on the affected computer:
  
  • C:\Program Files\Kaspersky Lab\
  • C:\Program Files (x86)\Kaspersky Lab\

(Note: %Common Startup% is the startup folder for all users, which is usually C:\Documents and Settings\All Users\Start Menu\Programs\Startup on Windows 2000, XP, and Server 2003, or C:\ProgramData\Microsoft\Windows\Start Menu\Programs\Startup on Windows Vista, 7, and 8.)