Backdoor.Win32.NANOCORE.TIAOODHN

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.

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.PDF.NANOCORE.AJ

Installation

This Backdoor drops the following files:

• %User Temp%\03836134\awgo.msc
• %User Temp%\03836134\dbfa.xml
• %User Temp%\03836134\dwbiukiwwg.bmp
• %User Temp%\03836134\eeaitaojpi.vog
• %User Temp%\03836134\emcnlopaex.bmp
• %User Temp%\03836134\extsxlbjs.xls
• %User Temp%\03836134\fulpcjqun.pif
• %User Temp%\03836134\hdpao.log
• %User Temp%\03836134\iwvudoaq.pdf
• %User Temp%\03836134\kjnsusd.txt
• %User Temp%\03836134\kvsqx.vbs
• %User Temp%\03836134\lujehq.bmp
• %User Temp%\03836134\mlvxqxapha.msc
• %User Temp%\03836134\mraln.docx
• %User Temp%\03836134\nqpxgrjps.ppt
• %User Temp%\03836134\ohrs.bmp
• %User Temp%\03836134\ovoa.docx
• %User Temp%\03836134\qcsx.msc
• %User Temp%\03836134\rvghvmkrj.msc
• %User Temp%\03836134\ssaf.ppt
• %User Temp%\03836134\uantmffea.cpl
• %User Temp%\03836134\uxgjq.icm
• %User Temp%\03836134\wmbdfbpme.msc
• %User Profile%\temp\nqpxgrjps.ppt
• %User Temp%\RegSvcs.exe
• %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
• %Program Files%\{String 1} {String 3}\{String 1}{String 2}.exe -> Admin privilege
• %Application Data%\{GUID}\{String 1} {String 3}\{String 1}{String 2}.exe -> User privilege

(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).. %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).. %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).)

It adds the following processes:

• "%User Temp%\RegSvcs.exe"
• "schtasks.exe" /create /f /tn "{String 1} {String 3} Task" /xml "%User Temp%\tmp{random characters}.tmp";
• "schtasks.exe" /create /f /tn "{String 1} {String 3}" /xml "%User Temp%\tmp{random characters}.tmp";
• "%User Temp%\03836134\fulpcjqun.pif" eeaitaojpi.vog

(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 creates the following folders:

• %User Profile%\temp
• %User Temp%\03836134
• %Program Files%\{String1} {String3}
• %Application Data%\{GUID}\Logs
• %Application Data%\{GUID}\Logs\{user name}
• %Application Data%\{GUID}

(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).. %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).. %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 adds the following mutexes to ensure that only one of its copies runs at any one time:

• Global\{GUID}

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 32-bit OS

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 32-bit OS

HKEY_LOCAL_MACHINE\SOFTWARE\WOW6432Node\
Microsoft\Windows\CurrentVersion\
Run
WindowsUpdate = "0\03836134\fulpcjqun.pif 0\03836134\eeaitaojpi.vog" -> 64-bit OS

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
WindowsUpdate = "0\03836134\fulpcjqun.pif 0\03836134\eeaitaojpi.vog" -> 32-bit OS

HKEY_LOCAL_MACHINE\SOFTWARE\WOW6432Node\
Microsoft\Windows\CurrentVersion\
Run
{String 1} {String 3} = %Program Files%\{String 1} {String 3}\{String 1}{String 2}.exe -> Admin privilege 64-bit OS

HKEY_LOCAL_MACHINE\SOFTWARE\WOW6432Node\
Microsoft\Windows\CurrentVersion\
Run
{String 1} {String 3} = %Application Data%\{GUID}\{String 1} {String 3}\{String 1}{String 2}.exe -> User privilege 64-bit OS

Backdoor Routine

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

• Manage its backdoor file:
  • Update itself
  • Restart itself
  • Terminate itself
  • Uninstall itself
  • Restart connection
  • Disconnect
  • Disable/Restore Protection
• 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:

• timnoip.{BLOCKED}s.net:9583
• {BLOCKED}.{BLOCKED}.225.15:9583

Information Theft

This Backdoor gathers the following data:

• 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:

• This backdoor inject the malicious codes to the following processes:
  • %User Temp%\RegSvcs.exe
• 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

(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 scheduled tasks:

• Task Name: {String 1} {String 3}
• Action: Start "%User Temp%\RegSvcs.exe" $(Arg0)
• Task Name: {String 1} {String 3} Task
• Action: Start "%Program Files%\{String 1} {String 3}\{String 1}{String 2}.exe" $(Arg0)

(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).. %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).)