Trojan.Win32.GREEDSERPENT.A
GenericRXBW-XR!EB8862A1F598 (McAfee)
Windows
Threat Type: Trojan
Destructiveness: No
Encrypted:
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.
It deletes itself after execution.
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 adds the following processes:
- %Windows%\Microsoft.NET\Framework\aspnet_wp.exe
- cmd.exe /c del "%User Temp%\bf4c091187acfe9866932692fff5758a4d998690.exe"
(Note: %Windows% is the Windows folder, where it usually is C:\Windows on all Windows operating system versions.. %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Local\Temp on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)
Autostart Technique
This Trojan registers itself as a system service to ensure its automatic execution at every system startup by adding the following registry entries:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\clr_optimization_v3.0.50727_64
ImagePath = "%Windows%\Microsoft.NET\Framework\mscorsvws.exe"
Other System Modifications
This Trojan adds the following registry keys:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
services\clr_optimization_v3.0.50727_64\Description
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
services\clr_optimization_v3.0.50727_64\Parameters
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
services\clr_optimization_v3.0.50727_64\Parameters\
Application
It adds the following registry entries:
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
services\clr_optimization_v3.0.50727_64
Displayname = "Microsoft .NET Framework NGEN v3.5.50727_X64"
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
services\clr_optimization_v3.0.50727_64
Description = "Microsoft .NET Framework NGEN."
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
services\clr_optimization_v3.0.50727_64\Parameters
Application = "aspnet_wp.exe"
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\clr_optimization_v3.0.50727_64
DisplayName = "clr_optimization_v3.0.50727_64"
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\clr_optimization_v3.0.50727_64
Start = "SERVICE_AUTO_START"
It modifies the following registry entries:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
services\LanmanServer
Start = "4"
(Note: The default value data of the said registry entry is 2.)
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
services\Schedule
Start = "4"
(Note: The default value data of the said registry entry is 2.)
Dropping Routine
This Trojan drops the following files:
- %Windows%\MpMgSvc.dll
(Note: %Windows% is the Windows folder, where it usually is C:\Windows on all Windows operating system versions.)
Other Details
This Trojan connects to the following possibly malicious URL:
- http://{BLOCKED}i.com
It deletes itself after execution.
This report is generated via an automated analysis system.
SOLUTION
Step 1
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 2
Identify and terminate files detected as Trojan.Win32.GREEDSERPENT.A
- Windows Task Manager may not display all running processes. In this case, please use a third-party process viewer, preferably Process Explorer, to terminate the malware/grayware/spyware file. You may download the said tool here.
- If the detected file is displayed in either Windows Task Manager or Process Explorer but you cannot delete it, restart your computer in safe mode. To do this, refer to this link for the complete steps.
- If the detected file is not displayed in either Windows Task Manager or Process Explorer, continue doing the next steps.
Step 3
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\services\clr_optimization_v3.0.50727_64
- Description
- In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\clr_optimization_v3.0.50727_64
- Parameters
- In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\clr_optimization_v3.0.50727_64\Parameters
- Application
Step 4
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\clr_optimization_v3.0.50727_64
- Displayname = "Microsoft .NET Framework NGEN v3.5.50727_X64"
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\services\clr_optimization_v3.0.50727_64
- Description = "Microsoft .NET Framework NGEN."
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\services\clr_optimization_v3.0.50727_64\Parameters
- Application = "aspnet_wp.exe"
- In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\clr_optimization_v3.0.50727_64
- DisplayName = "clr_optimization_v3.0.50727_64"
- In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\clr_optimization_v3.0.50727_64
- Start = "SERVICE_AUTO_START"
Step 5
Restore these modified registry values
Important:Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this only if you know how to or you can seek your system administrator's help. You may also check out this Microsoft article first before modifying your computer's registry.
- In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\LanmanServer
- From: Start = "4"
To: Start = ""2""
- From: Start = "4"
- In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\Schedule
- From: Start = "4"
To: Start = ""2""
- From: Start = "4"
Step 6
Search and delete this file
- %Windows%\MpMgSvc.dll
Step 7
Scan your computer with your Trend Micro product to delete files detected as Trojan.Win32.GREEDSERPENT.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 the following Trend Micro Support pages for more information:
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