WORM_NITOL.JG
DDoS:Win32/Nitol.A (Microsoft), Virus.Win32.Dzan.a (KASPERSKY), Win32/ServStart.AC trojan (NOD32)
Windows
Threat Type: Worm
Destructiveness: No
Encrypted:
In the wild: Yes
OVERVIEW
This worm arrives via removable drives. It 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 worm arrives via removable drives.
It 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 worm drops the following component file(s):
- %System%\{random}.exe
(Note: %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.)
It drops the following copies of itself into the affected system:
- %System%\hra33.dll
(Note: %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.)
Autostart Technique
This worm registers its dropped component as a system service to ensure its automatic execution at every system startup. It does this by creating the following registry entries:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\Nationalgnf
ImagePath = "%System%\{random file name}.exe"
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\Nationalgnf
Description = "Providesgkl a domain server for NI security"
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\Nationalgnf
DisplayName = "Nationaltdb Instruments Domain Service"
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\Nationalgnf
ErrorControl = "0"
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\Nationalgnf
ObjectName = "LocalSystem"
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\Nationalgnf
Start = "2"
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\Nationalgnf
Type = "10"
Other System Modifications
This worm adds the following registry keys:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\Nationalgnf\Enum
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\Nationalgnf\Security
Other Details
This worm connects to the following possibly malicious URL:
- http://dd.{BLOCKED}nren.com
NOTES:
This worm drops the following copy of itself in all folders in all physical and removable drives containing an EXE file:
- lpk.dll
It drops the following copy of the dropped component file every time it is run:
- %User Temp%\hrl{2 random characters}.tmp
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
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 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\CurrentControlSet\Services\Nationalgnf
- ImagePath = "%System%\{random file name}.exe"
- ImagePath = "%System%\{random file name}.exe"
- In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Nationalgnf
- Description = "Providesgkl a domain server for NI security"
- Description = "Providesgkl a domain server for NI security"
- In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Nationalgnf
- DisplayName = "Nationaltdb Instruments Domain Service"
- DisplayName = "Nationaltdb Instruments Domain Service"
- In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Nationalgnf
- ErrorControl = "0"
- ErrorControl = "0"
- In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Nationalgnf
- ObjectName = "LocalSystem"
- ObjectName = "LocalSystem"
- In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Nationalgnf
- Start = "2"
- Start = "2"
- In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Nationalgnf
- Type = "10"
- Type = "10"
Step 4
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.
- HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Nationalgnf\Enum
- HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Nationalgnf\Security
Step 5
Search and delete these files
- %System%\{random}.exe
- %User Temp%\hrl{2 random characters}.tmp
Step 6
Scan your computer with your Trend Micro product to clean files detected as WORM_NITOL.JG. 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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