BKDR_NETCLR.A
Trojan:Win32/Beaugrit.gen!AAA (Microsoft); Trojan.Win32.Vehidis.arj (Kaspersky); Trojan.Win32.Generic!BT (Sunbelt); Trojan horse Crypt3.AHCD (AVG)
Windows 2000, Windows Server 2003, Windows XP (32-bit, 64-bit), Windows Vista (32-bit, 64-bit), Windows 7 (32-bit, 64-bit)
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.
It deletes itself after execution.
TECHNICAL DETAILS
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:
- %Windows%\eeosec.exe
- \.\fuck360
(Note: %Windows% is the Windows folder, which is usually C:\Windows.)
It creates the following folders:
- %Start Menu%\Programs\Startupÿ
(Note: %Start Menu% is the current user's Start Menu folder, which is usually C:\Windows\Start Menu or C:\Documents and Settings\{User name}\Start Menu on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Roaming\Microsoft\Windows\Start Menu on Windows Vista and 7.)
Other System Modifications
This backdoor adds the following registry keys:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Control\MediaResources\msvideo
It adds the following registry entries:
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\.Net CLR
Description = "Microsoft .NET and Windows XP COM+ Integration with SOAP"
Dropping Routine
This backdoor drops the following files:
- %System Root%\5375.vbs
(Note: %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.)
Other Details
This backdoor connects to the following possibly malicious URL:
- {BLOCKED}28.241
It deletes itself after execution.
This report is generated via an automated analysis system.
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.
- In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\MediaResources
- msvideo
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_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\.Net CLR
- Description = "Microsoft .NET and Windows XP COM+ Integration with SOAP"
Step 4
Search and delete this file
- %System Root%\5375.vbs
Step 5
Search and delete this folder
- %Start Menu%\Programs\Startupÿ
Step 6
Scan your computer with your Trend Micro product to delete files detected as BKDR_NETCLR.A. 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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