BKDR_NANOCORE.YAKL
Trojan:Win32/Dynamer!ac (Microsoft); RDN/Generic.grp (McAfee); Trojan.Gen.2 (Symantec); Backdoor.MSIL.NanoBot.wkv (Kaspersky); Trojan.Win32.Generic!BT (Sunbelt); Trojan horse Pakes3_c.RFC (AVG)
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
450,560 bytes
EXE
No
12 Jun 2017
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 creates the following folders:
- %User Profile%\Application Data\6ABCE574-4AFC-42C5-8AB9-5739A84D8A8B
- %User Profile%\6ABCE574-4AFC-42C5-8AB9-5739A84D8A8B\Logs
- %User Profile%\Logs\Wilbert
(Note: %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.)
Other System Modifications
This Backdoor deletes the following files:
- {malware path and file name}.installstate
- %Windows%\Microsoft.NET\Framework\v2.0.50727\RegAsm.exe:Zone.Identifier
- %User Profile%\6ABCE574-4AFC-42C5-8AB9-5739A84D8A8B\settings.bak
(Note: %Windows% is the Windows folder, where it usually is C:\Windows on all Windows operating system versions.. %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.)
It adds the following registry keys:
HKEY_CURRENT_USER\Software\Microsoft\
Windows Script\Settings
It adds the following registry entries:
HKEY_CURRENT_USER\Software\Microsoft\
Windows Script\Settings
JITDebug = "0"
Dropping Routine
This Backdoor drops the following files:
- %User Profile%\6ABCE574-4AFC-42C5-8AB9-5739A84D8A8B\run.dat
- %User Profile%\6ABCE574-4AFC-42C5-8AB9-5739A84D8A8B\catalog.dat
- %User Profile%\6ABCE574-4AFC-42C5-8AB9-5739A84D8A8B\storage.dat
- %User Profile%\6ABCE574-4AFC-42C5-8AB9-5739A84D8A8B\settings.bin
- %User Temp%\z5tv05rw.w4k
(Note: %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.. %User Temp% is the user's temporary folder, where it usually is C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local\Temp 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.)
This report is generated via an automated analysis system.
SOLUTION
9.8
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
Delete this registry key
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 Script
- Settings
Step 3
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 Script\Settings
- JITDebug = "0"
Step 4
Search and delete these components
- %User Profile%\6ABCE574-4AFC-42C5-8AB9-5739A84D8A8B\run.dat
- %User Profile%\6ABCE574-4AFC-42C5-8AB9-5739A84D8A8B\catalog.dat
- %User Profile%\6ABCE574-4AFC-42C5-8AB9-5739A84D8A8B\storage.dat
- %User Profile%\6ABCE574-4AFC-42C5-8AB9-5739A84D8A8B\settings.bin
- %User Temp%\z5tv05rw.w4k
Step 5
Search and delete these folders
- %User Profile%\Application Data\6ABCE574-4AFC-42C5-8AB9-5739A84D8A8B
- %User Profile%\6ABCE574-4AFC-42C5-8AB9-5739A84D8A8B\Logs
- %User Profile%\Logs\Wilbert
Step 6
Scan your computer with your Trend Micro product to delete files detected as BKDR_NANOCORE.YAKL. 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.
Step 7
Restore this file from backup only Microsoft-related files will be restored. If this malware/grayware also deleted files related to programs that are not from Microsoft, please reinstall those programs on you computer again.
- {malware path and file name}.installstate
- %Windows%\Microsoft.NET\Framework\v2.0.50727\RegAsm.exe:Zone.Identifier
- %User Profile%\6ABCE574-4AFC-42C5-8AB9-5739A84D8A8B\settings.bak
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