WORM_LINEAGE.DDW
Worm:Win32/Taterf.B (Microsoft); Generic PWS.ak (McAfee); W32.Gammima (Symantec); Packed.Win32.Krap.g (Kaspersky); Worm.Win32.Taterf.b (v) (Sunbelt); Win32/Heur (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
176,128 bytes
EXE
Yes
04 Apr 2013
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.
Installation
This worm drops the following copies of itself into the affected system:
- %System%\kvosoft.exe
(Note: %System% is the Windows system folder, which is usually C:\Windows\System32.)
Autostart Technique
This worm adds the following registry entries to enable its automatic execution at every system startup:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
kvasoft = "%System%\kvosoft.exe"
It registers itself as a BHO to ensure its automatic execution every time Internet Explorer is used by adding the following registry keys:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Explorer\
Browser Helper Objects\{CE7C3CF0-4B15-11D1-ABED-709549C10000}
It 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\KAVsys
Other System Modifications
This worm deletes the following files:
- %System Root%\6asmuyut.exe
(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_CLASSES_ROOT\IEHlprObj.IEHlprObj.1
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
IEHlprObj.IEHlprObj.1\CLSID
HKEY_CLASSES_ROOT\IEHlprObj.IEHlprObj
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
IEHlprObj.IEHlprObj\CurVer
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{CE7C3CF0-4B15-11D1-ABED-709549C10000}
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{CE7C3CF0-4B15-11D1-ABED-709549C10000}\ProgID
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{CE7C3CF0-4B15-11D1-ABED-709549C10000}\VersionIndependentProgID
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{CE7C3CF0-4B15-11D1-ABED-709549C10000}\Programmable
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{CE7C3CF0-4B15-11D1-ABED-709549C10000}\InprocServer32
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Explorer\
Browser Helper Objects
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
TypeLib\{CE7C3CE2-4B15-11D1-ABED-709549C10000}
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
TypeLib\{CE7C3CE2-4B15-11D1-ABED-709549C10000}\1.0
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
TypeLib\{CE7C3CE2-4B15-11D1-ABED-709549C10000}\1.0\
FLAGS
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
TypeLib\{CE7C3CE2-4B15-11D1-ABED-709549C10000}\1.0\
0
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
TypeLib\{CE7C3CE2-4B15-11D1-ABED-709549C10000}\1.0\
0\win32
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
TypeLib\{CE7C3CE2-4B15-11D1-ABED-709549C10000}\1.0\
HELPDIR
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Interface\{CE7C3CEF-4B15-11D1-ABED-709549C10000}
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Interface\{CE7C3CEF-4B15-11D1-ABED-709549C10000}\ProxyStubClsid
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Interface\{CE7C3CEF-4B15-11D1-ABED-709549C10000}\ProxyStubClsid32
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Interface\{CE7C3CEF-4B15-11D1-ABED-709549C10000}\TypeLib
It adds the following registry entries:
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\KAVsys
Type = "1"
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\KAVsys
ErrorControl = "1"
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\KAVsys
Start = "1"
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\KAVsys
ImagePath = "\??\%System%\drivers\klif.sys"
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{CE7C3CF0-4B15-11D1-ABED-709549C10000}\InprocServer32
ThreadingModel = "Apartment"
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Interface\{CE7C3CEF-4B15-11D1-ABED-709549C10000}\TypeLib
Version = "1.0"
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
ShowSuperHidden = "0"
It modifies the following registry entries:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
Hidden = "2"
(Note: The default value data of the said registry entry is 2.)
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced\Folder\Hidden\
SHOWALL
CheckedValue = "0"
(Note: The default value data of the said registry entry is 1.)
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
Explorer
NoDriveTypeAutoRun = "91"
(Note: The default value data of the said registry entry is 91.)
It deletes the following registry keys:
HKEY_LOCAL_MACHINE\System\CurrentControlSet\
Services\KAVsys\Enum
HKEY_LOCAL_MACHINE\System\CurrentControlSet\
Services\KAVsys\Security
Dropping Routine
This worm drops the following files:
- %System%\drivers\klif.sys
- %System%\hgkjghg0.dll
- %System%\dsetwem0.dll
- %System Root%\autorun.inf
- %System Root%\6asmuyut.exe
(Note: %System% is the Windows system folder, which is usually C:\Windows\System32.. %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.)
Other Details
This worm connects to the following possibly malicious URL:
- http://{BLOCKED}k.com/xhg2/ll1.rar
This report is generated via an automated analysis system.
SOLUTION
9.300
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
Close all opened browser windows
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.
- In HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services
- KAVsys
- In HKEY_CLASSES_ROOT
- IEHlprObj.IEHlprObj.1
- In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\IEHlprObj.IEHlprObj.1
- CLSID
- In HKEY_CLASSES_ROOT
- IEHlprObj.IEHlprObj
- In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\IEHlprObj.IEHlprObj
- CurVer
- In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID
- {CE7C3CF0-4B15-11D1-ABED-709549C10000}
- In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{CE7C3CF0-4B15-11D1-ABED-709549C10000}
- ProgID
- In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{CE7C3CF0-4B15-11D1-ABED-709549C10000}
- VersionIndependentProgID
- In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{CE7C3CF0-4B15-11D1-ABED-709549C10000}
- Programmable
- In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{CE7C3CF0-4B15-11D1-ABED-709549C10000}
- InprocServer32
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer
- Browser Helper Objects
- In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\TypeLib
- {CE7C3CE2-4B15-11D1-ABED-709549C10000}
- In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\TypeLib\{CE7C3CE2-4B15-11D1-ABED-709549C10000}
- 1.0
- In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\TypeLib\{CE7C3CE2-4B15-11D1-ABED-709549C10000}\1.0
- FLAGS
- In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\TypeLib\{CE7C3CE2-4B15-11D1-ABED-709549C10000}\1.0
- 0
- In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\TypeLib\{CE7C3CE2-4B15-11D1-ABED-709549C10000}\1.0\0
- win32
- In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\TypeLib\{CE7C3CE2-4B15-11D1-ABED-709549C10000}\1.0
- HELPDIR
- In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Interface
- {CE7C3CEF-4B15-11D1-ABED-709549C10000}
- In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Interface\{CE7C3CEF-4B15-11D1-ABED-709549C10000}
- ProxyStubClsid
- In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Interface\{CE7C3CEF-4B15-11D1-ABED-709549C10000}
- ProxyStubClsid32
- In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Interface\{CE7C3CEF-4B15-11D1-ABED-709549C10000}
- TypeLib
Step 5
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_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
- kvasoft = "%System%\kvosoft.exe"
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\KAVsys
- Type = "1"
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\KAVsys
- ErrorControl = "1"
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\KAVsys
- Start = "1"
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\KAVsys
- ImagePath = "\??\%System%\drivers\klif.sys"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{CE7C3CF0-4B15-11D1-ABED-709549C10000}\InprocServer32
- ThreadingModel = "Apartment"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Interface\{CE7C3CEF-4B15-11D1-ABED-709549C10000}\TypeLib
- Version = "1.0"
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
- ShowSuperHidden = "0"
Step 6
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_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
- From: Hidden = "2"
To: Hidden = ""2""
- From: Hidden = "2"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Advanced\Folder\Hidden\SHOWALL
- From: CheckedValue = "0"
To: CheckedValue = ""1""
- From: CheckedValue = "0"
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer
- From: NoDriveTypeAutoRun = "91"
To: NoDriveTypeAutoRun = ""91""
- From: NoDriveTypeAutoRun = "91"
Step 7
Search and delete these components
- %System%\drivers\klif.sys
- %System%\hgkjghg0.dll
- %System%\dsetwem0.dll
- %System Root%\autorun.inf
- %System Root%\6asmuyut.exe
Step 8
Restart in normal mode and scan your computer with your Trend Micro product for files detected as WORM_LINEAGE.DDW. 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 9
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%\6asmuyut.exe
Step 10
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\System\CurrentControlSet\Services\KAVsys
- Enum
- In HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\KAVsys
- Security
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