Backdoor.Win32.NANOCORE.TIAOODFQ
Backdoor:Win32/NetWiredRC!MTB (Microsoft); Trojan.Win32.Vebzenpak.cye (Kaspersky)
Windows
![](/vinfo/imgFiles/legend.jpg)
Threat Type: Backdoor
Destructiveness: No
Encrypted:
In the wild: Yes
OVERVIEW
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.
TECHNICAL DETAILS
49,152 bytes
EXE
Yes
17 Feb 2020
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:
- %User Profile%\subfolder1\filename1.exe
(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).)
It drops the following files:
- %Application Data%\{GUID}\catalog.dat
- %Application Data%\{GUID}\run.dat
- %Application Data%\{GUID}\settings.bin
- %Application Data%\{GUID}\storage.dat
- %Application Data%\{GUID}\task.dat
- %Application Data%\{GUID}\Logs\{Username}\KB_{random numbers}.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).)
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\RunOnce
Startup key = "%User Profile%\subfolder1\filename1.exe"
Other Details
This Backdoor connects to the following possibly malicious URL:
- https://drive.{BLOCKED}e.com/{BLOCKED}7f3jUw-vKq46BbnHrLJDHarc
- doc-0c-50-docs.{BLOCKED}usercontent.com
It adds the following scheduled tasks:
- Name: PCI Service
- Actions: “%Windows%\Microsoft.NET\Framework\{version}\RegAsm.exe” $(Arg0)
(Note: %Windows% is the Windows folder, where it usually is C:\Windows on all Windows operating system versions.)
SOLUTION
9.850
15.692.02
18 Feb 2020
15.693.00
19 Feb 2020
Step 1
Trend Micro Predictive Machine Learning detects and blocks malware at the first sign of its existence, before it executes on your system. When enabled, your Trend Micro product detects this malware under the following machine learning name:
- Troj.Win32.TRX.XXPE50FFF033
Step 2
Before doing any scans, Windows 7, Windows 8, Windows 8.1, and Windows 10 users must disable System Restore to allow full scanning of their computers.
Step 3
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 4
Restart in Safe Mode
Step 5
Delete this registry value
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\CurrentVersion\RunOnce
- Startup key = "%User Profile%\subfolder1\filename1.exe"
- Startup key = "%User Profile%\subfolder1\filename1.exe"
Step 6
Deleting Scheduled Tasks
The following {Task Name} - {Task to be run} listed should be used in the steps identified below:
- PCI Service - “%Windows%\Microsoft.NET\Framework\{version}\RegAsm.exe” $(Arg0)
For Windows 2000, Windows XP, and Windows Server 2003:
- Open the Windows Scheduled Tasks. Click Start>Programs>Accessories>
System Tools>Scheduled Tasks. - Locate each {Task Name} values listed above in the Name column.
- Right-click on the said file(s) with the aforementioned value.
- Click on Properties. In the Run field, check for the listed {Task to be run}.
- If the strings match the list above, delete the task.
For Windows Vista, Windows 7, Windows Server 2008, Windows 8, Windows 8.1, and Windows Server 2012:
- 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. - In the left panel, click Task Scheduler Library.
- In the upper-middle panel, locate each {Task Name} values listed above in the Name column.
- In the lower-middle panel, click the Actions tab. In the Details column, check for the {Task to be run} string.
- If the said string is found, delete the task.
Step 7
Search and delete this file
- %User Profile%\subfolder1\filename1.exe
- %Application Data%\{GUID}\catalog.dat
- %Application Data%\{GUID}\run.dat
- %Application Data%\{GUID}\settings.bin
- %Application Data%\{GUID}\storage.dat
- %Application Data%\{GUID}\task.dat
- %Application Data%\{GUID}\Logs\{Username}\KB_{random numbers}.dat
Step 8
Restart in normal mode and scan your computer with your Trend Micro product for files detected as Backdoor.Win32.NANOCORE.TIAOODFQ. 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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