WORM_NACO.E
Worm:Win32/Naco.E@mm.dr (Microsoft); W32/Naco.e@MM (McAfee); W32.Naco.C@mm (Symantec); Email-Worm.Win32.Nocana.d (Kaspersky); Trojan.Win32.Generic!BT (Sunbelt); I-Worm/Naco (AVG)
Windows 2000, Windows XP, Windows Server 2003

Threat Type: Worm
Destructiveness: No
Encrypted:
In the wild: Yes
OVERVIEW
This worm 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 on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.
Autostart Technique
This worm adds the following registry entries to enable its automatic execution at every system startup:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
ALM = "%System%\ANACON32.EXE"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\RunServices
Services = "%System%\ANACON32.EXE"
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
Under20 = "%System%\ANACON32.EXE"
Other System Modifications
This worm deletes the following files:
- %System Root%\ANACON.BAT
(Note: %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.)
It adds the following registry keys:
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{248DD896-BB45-11CF-9ABC-0080C7E7B78D}\Control
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
TypeLib\{248DD890-BB45-11CF-9ABC-0080C7E7B78D}
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
TypeLib\{248DD890-BB45-11CF-9ABC-0080C7E7B78D}\1.0\
0
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\RunServices
HKEY_CURRENT_USER\Software\Mirabilis\
ICQ\Agent\Apps\
Administrator
It adds the following registry entries:
HKEY_CURRENT_USER\Software\Mirabilis\
ICQ\Agent\Apps\
Administrator
Startup = "%System%"
HKEY_CURRENT_USER\Software\Mirabilis\
ICQ\Agent\Apps\
Administrator
Enable = "Yes"
HKEY_CURRENT_USER\Software\Mirabilis\
ICQ\Agent\Apps\
Administrator
Path = "%System%\ANACON32.EXE"
It modifies the following registry entries:
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{248DD896-BB45-11CF-9ABC-0080C7E7B78D}\InprocServer32
ThreadingModel = "Apartment"
(Note: The default value data of the said registry entry is Apartment.)
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Interface\{248DD892-BB45-11CF-9ABC-0080C7E7B78D}\TypeLib
Version = "1.0"
(Note: The default value data of the said registry entry is 1.0.)
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Interface\{248DD893-BB45-11CF-9ABC-0080C7E7B78D}\TypeLib
Version = "1.0"
(Note: The default value data of the said registry entry is 1.0.)
It deletes the following registry keys:
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{248DD896-BB45-11CF-9ABC-0080C7E7B78D}
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{248DD897-BB45-11CF-9ABC-0080C7E7B78D}
Dropping Routine
This worm drops the following files:
- %System Root%/ANACON.BAT
- %System Root%/MSWINSCK.OCX
- %System Root%/NACO.exe
- %Program Files%\MSWINSCK.OCX
- %System%\ANACON32.EXE
- %System%\MSWINSCK.OCX
- %System%\MSVBVM60.DLL
(Note: %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.. %Program Files% is the default Program Files folder, usually C:\Program Files in Windows 2000, Server 2003, and XP (32-bit), Vista (32-bit), and 7 (32-bit), or C:\Program Files (x86) in Windows XP (64-bit), Vista (64-bit), and 7 (64-bit).. %System% is the Windows system folder, which is usually C:\Windows\System32.)
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
Restart in Safe Mode
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\SOFTWARE\Classes\CLSID\{248DD896-BB45-11CF-9ABC-0080C7E7B78D}
- Control
- In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\TypeLib
- {248DD890-BB45-11CF-9ABC-0080C7E7B78D}
- In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\TypeLib\{248DD890-BB45-11CF-9ABC-0080C7E7B78D}\1.0
- 0
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion
- RunServices
- In HKEY_CURRENT_USER\Software\Mirabilis\ICQ\Agent\Apps
- Administrator
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\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
- ALM = "%System%\ANACON32.EXE"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\RunServices
- Services = "%System%\ANACON32.EXE"
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
- Under20 = "%System%\ANACON32.EXE"
- In HKEY_CURRENT_USER\Software\Mirabilis\ICQ\Agent\Apps\Administrator
- Startup = "%System%"
- In HKEY_CURRENT_USER\Software\Mirabilis\ICQ\Agent\Apps\Administrator
- Enable = "Yes"
- In HKEY_CURRENT_USER\Software\Mirabilis\ICQ\Agent\Apps\Administrator
- Path = "%System%\ANACON32.EXE"
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\SOFTWARE\Classes\CLSID\{248DD896-BB45-11CF-9ABC-0080C7E7B78D}\InprocServer32
- From: ThreadingModel = "Apartment"
To: ThreadingModel = ""Apartment""
- From: ThreadingModel = "Apartment"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Interface\{248DD892-BB45-11CF-9ABC-0080C7E7B78D}\TypeLib
- From: Version = "1.0"
To: Version = ""1.0""
- From: Version = "1.0"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Interface\{248DD893-BB45-11CF-9ABC-0080C7E7B78D}\TypeLib
- From: Version = "1.0"
To: Version = ""1.0""
- From: Version = "1.0"
Step 6
Search and delete these components
- %System Root%/ANACON.BAT
- %System Root%/MSWINSCK.OCX
- %System Root%/NACO.exe
- %Program Files%\MSWINSCK.OCX
- %System%\ANACON32.EXE
- %System%\MSWINSCK.OCX
- %System%\MSVBVM60.DLL
Step 7
Restart in normal mode and scan your computer with your Trend Micro product for files detected as WORM_NACO.E. 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 8
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.
- %System Root%\ANACON.BAT
Step 9
Restore these deleted registry keys/values from backup
*Note: Only Microsoft-related keys/values will be restored. If the malware/grayware also deleted registry keys/values related to programs that are not from Microsoft, please reinstall those programs on your computer.
- In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID
- {248DD896-BB45-11CF-9ABC-0080C7E7B78D}
- In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID
- {248DD897-BB45-11CF-9ABC-0080C7E7B78D}
Did this description help? Tell us how we did.