Analysis by: Augusto II Remillano
ALIASES:

Backdoor:MSIL/Noancooe.C (Microsoft), Trojan.Nancrat (Norton), HEUR:Trojan.MSIL.NanoBot.gen (Kaspersky)

 PLATFORM:

Windows

 OVERALL RISK RATING:
 DAMAGE POTENTIAL:
 DISTRIBUTION POTENTIAL:
 REPORTED INFECTION:
 INFORMATION EXPOSURE:

  • Threat Type: Backdoor

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

Infection Channel: Dropped by other malware, Downloaded from the Internet

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.

  TECHNICAL DETAILS

File Size: 1,314,584 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 12 Nov 2018
Payload: Compromises system security, Connects to URLs/IPs, Steals information

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 a copy of itself in the following folders using different file names:

  • %Application Data%\{GUID}\PCI Service\pcisv.exe
  • %Application Data%\FolderN\name.exe
  • %Program Files%\PCI Service\pcisv.exe

(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, XP, and Server 2003, or C:\Users\{user name}\AppData\Roaming on Windows Vista, 7, and 8.. %Program Files% is the default Program Files folder, usually C:\Program Files in Windows 2000, Server 2003, and XP (32-bit), Vista (32-bit), 7 (32-bit), and 8 (32-bit), or C:\Program Files (x86) in Windows XP (64-bit), Vista (64-bit), 7 (64-bit), and 8 (64-bit).)

It drops the following files:

  • %Application Data%\{GUID}\run.dat
  • %Application Data%\{GUID}\task.dat
  • %Application Data%\{GUID}\Logs\{user name}\KB_{random}.dat
  • %Application Data%\{GUID}\settings.bin
  • %Application Data%\tmp.exe
  • %User Temp%\svhost.exe
  • %Application Data%\{GUID}\PCI Service\pcisv.exe

(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, XP, and Server 2003, or C:\Users\{user name}\AppData\Roaming on Windows Vista, 7, and 8.. %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista, 7, and 8.)

It creates the following folders:

  • %Program Files%\PCI Service
  • %Application Data%\FolderN
  • %Application Data%\{GUID}
  • %Application Data%\{GUID}\Logs
  • %Application Data%\{GUID}\Logs\{user name}

(Note: %Program Files% is the default Program Files folder, usually C:\Program Files in Windows 2000, Server 2003, and XP (32-bit), Vista (32-bit), 7 (32-bit), and 8 (32-bit), or C:\Program Files (x86) in Windows XP (64-bit), Vista (64-bit), 7 (64-bit), and 8 (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, XP, and Server 2003, or C:\Users\{user name}\AppData\Roaming on Windows Vista, 7, and 8.)

Autostart Technique

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

HKEY_CURRENT_USER\Software\Microsoft\
Windows NT\CurrentVersion\Windows
Load = %Application Data%\FolderN\name.exe.lnk

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
PCI Service = %Program Files%\PCI Service\pcisv.exe

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
PCI Service = %Application Data%\{GUID}\PCI Service\pcisv.exe

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}.217.189:22401

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 adds the following scheduled tasks:

  • Name: PCI Service Task
    Action: Start a program "%Program Files%\PCI Service\pcisv.exe" $(Arg0)
  • Name: PCI Service
    Action: Start a program “{Malware filepath}” $(Arg0)

(Note: %Program Files% is the default Program Files folder, usually C:\Program Files in Windows 2000, Server 2003, and XP (32-bit), Vista (32-bit), 7 (32-bit), and 8 (32-bit), or C:\Program Files (x86) in Windows XP (64-bit), Vista (64-bit), 7 (64-bit), and 8 (64-bit).)

  SOLUTION

Minimum Scan Engine: 9.850
FIRST VSAPI PATTERN FILE: 14.636.05
FIRST VSAPI PATTERN DATE: 19 Nov 2018
VSAPI OPR PATTERN File: 14.637.00
VSAPI OPR PATTERN Date: 20 Nov 2018

Step 1

Before doing any scans, Windows XP, Windows Vista, and Windows 7 users must disable System Restore to allow full scanning of their computers.

Step 2

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 3

Restart in Safe Mode

[ Learn More ]

Step 4

Delete this registry value

[ Learn More ]

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_CURRENT_USER\Software\Microsoft\Windows NT\CurrentVersion\Windows
    • Load = %Application Data%\FolderN\name.exe.lnk
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    • PCI Service = %Program Files%\PCI Service\pcisv.exe
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • PCI Service = %Application Data%\{GUID}\PCI Service\pcisv.exe

Step 5

Deleting Scheduled Tasks

For Windows 2000, Windows XP, and Windows Server 2003:

  1. Open the Windows Scheduled Tasks. Click Start>Programs>Accessories>
    System Tools>Scheduled Tasks.
  2. Locate each task that has the following value in the Schedule column:
    • PCI Service
    • PCI Service Task
  3. Right-click on the said file(s) with the aforementioned value.
  4. Click on Properties. In the Run field, check for the following string:
    Cmd /c /rd /s /q C:
  5. If the said string is found, delete the task.

For Windows Vista, Windows 7, Windows Server 2008, Windows 8, Windows 8.1, and Windows Server 2012:

  1. Open the Windows Task Scheduler. To do this:
    • On Windows Vista, Windows 7, and Windows Server 2008, click Start, type taskschd.msc in the Search input field, then press Enter.
    • On Windows 8, Windows 8.1, and Windows Server 2012, right-click on the lower left corner of the screen, click Run, type taskschd.msc, then press Enter.
  2. In the left panel, click Task Scheduler Library.
  3. In the upper-middle panel, locate each task that has the value in the Triggers column:
    • PCI Service
    • PCI Service Task
  4. In the lower-middle panel, click the Actions tab. In the Details column, check for the following string:
    Cmd /c /rd /s /q C:
  5. If the said string is found, delete the task..

Step 6

Search and delete these folders

[ Learn More ]
Please make sure you check the Search Hidden Files and Folders checkbox in the More advanced options option to include all hidden folders in the search result.
  • %Application Data%\FolderN
  • %Application Data%\{GUID}
  • %Program Files%\PCI Service

Step 7

Search and delete this file

[ Learn More ]
There may be some files that are hidden. Please make sure you check the Search Hidden Files and Folders checkbox in the "More advanced options" option to include all hidden files and folders in the search result.
  • %Application Data%\{GUID}\run.dat
  • %Application Data%\{GUID}\task.dat
  • %Application Data%\{GUID}\Logs\{user name}\KB_{random}.dat
  • %Application Data%\{GUID}\settings.bin
  • %Application Data%\tmp.exe
  • %User Temp%\svhost.exe
  • %Application Data%\{GUID}\PCI Service\pcisv.exe

Step 8

Restart in normal mode and scan your computer with your Trend Micro product for files detected as BKDR_NOANCOOE.AOOIAI. 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.


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