TROJ_DARKNEURON.B
Windows
Threat Type: Trojan
Destructiveness: No
Encrypted: Yes
In the wild: Yes
OVERVIEW
This Trojan 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
Arrival Details
This Trojan 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 Trojan drops the following files:
- {malware path}\System.Web.Helpers.dll
- %System%\w3wpdiag.exe
- %System%\System.Web.Helpers.dll
- %System%\InstallUtil.InstallLog
- %System%\w3wpdiag.InstallLog
- %System%\w3wpdiag.InstallState
(Note: %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.)
Autostart Technique
This Trojan registers as a system service to ensure its automatic execution at every system startup by adding the following registry keys:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
services\W3WPDIAG
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
services\W3WPDIAG
Type = 10
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
services\W3WPDIAG
Start = 2
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
services\W3WPDIAG
ErrorControl = 1
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
services\W3WPDIAG
ImagePath = "%System%\w3wpdiag.exe"
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
services\W3WPDIAG
DisplayName = "Microsoft IIS Diagnostics Service"
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
services\W3WPDIAG
ObjectName = "LocalSystem"
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
services\W3WPDIAG
Description = "Host service for the Microsoft IIS management provider. If this service is stopped or disabled, Microsoft IIS cannot be managed."
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
services\W3WPDIAG
DelayedAutostart = 0
Other Details
This Trojan does the following:
- It executes the following command lines:
- cmd.exe /c w3wpdiag.exe -install
- cmd.exe /c del *.InstallLog *.InstallState
SOLUTION
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. Before you could do this, you must restart in Safe Mode. For instructions on how to do this, you may refer to this page If the preceding step requires you to restart in safe mode, you may proceed to edit the system registry.
- In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services
- W3WPDIAG
- W3WPDIAG
Step 3
Search and delete this file
Step 4
Scan your computer with your Trend Micro product to delete files detected as TROJ_DARKNEURON.B. 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.
Did this description help? Tell us how we did.