WORM_AUTORUN.SAC
Packed.Win32.Krap.b [Kaspersky], Worm:Win32/Taterf.B [Microsoft]
Windows 2000, Windows XP, Windows Server 2003
![](/vinfo/imgFiles/legend.jpg)
Threat Type: Worm
Destructiveness: No
Encrypted: Yes
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.
It drops an AUTORUN.INF file to automatically execute the copies it drops when a user accesses the drives of an affected system.
As of this writing, the said sites are inaccessible.
TECHNICAL DETAILS
169,597 bytes
EXE
Yes
18 Feb 2009
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%\dse235rgd0.dll
- %System%\wedasgads0.dll
(Note: %System% is the Windows system folder, which is usually C:\Windows\System on Windows 98 and ME, C:\WINNT\System32 on Windows NT and 2000, or C:\Windows\System32 on Windows XP and Server 2003.)
It drops the following copies of itself into the affected system:
- %System%\kxvo.exe
(Note: %System% is the Windows system folder, which is usually C:\Windows\System on Windows 98 and ME, C:\WINNT\System32 on Windows NT and 2000, or C:\Windows\System32 on Windows XP and Server 2003.)
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
kxva = "%System%\kxvo.exe"
Other System Modifications
This worm adds the following registry keys:
HKEY_CLASSES_ROOT\IEHlprObj.IEHlprObj
HKEY_CLASSES_ROOT\CLSID\{CE7C3CF0-4B15-11D1-ABED-709549C10000}
HKEY_CLASSES_ROOT\Interface\{CE7C3CEF-4B15-11D1-ABED-709549C10000}
HKEY_CLASSES_ROOT\TypeLib\{CE7C3CE2-4B15-11D1-ABED-709549C10000}
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Explorer\
Browser Helper Objects\{CE7C3CF0-4B15-11D1-ABED-709549C10000}
It modifies the following registry entries to hide files with Hidden attributes:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
Hidden = "2"
(Note: The default value data of the said registry entry is 1.)
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
ShowSuperHidden = "0"
(Note: The default value data of the said registry entry is 1.)
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.)
Propagation
This worm drops the following copy of itself in all physical and removable drives:
- uaacifr.cmd
It drops an AUTORUN.INF file to automatically execute the copies it drops when a user accesses the drives of an affected system.
Download Routine
This worm accesses the following websites to download files:
- http://{BLOCKED}5.com/hg2/ll.rar
As of this writing, the said sites are inaccessible.
SOLUTION
8.900
5.854.05
18 Feb 2009
Step 1
For Windows XP and Windows Server 2003 users, before doing any scans, please make sure you disable System Restore to allow full scanning of your computer.
Step 2
Restart in Safe Mode
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_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
- kxva = "%System%\kxvo.exe"
- kxva = "%System%\kxvo.exe"
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_CLASSES_ROOT
- IEHlprObj.IEHlprObj
- IEHlprObj.IEHlprObj
- In HKEY_CLASSES_ROOT\CLSID
- {CE7C3CF0-4B15-11D1-ABED-709549C10000}
- {CE7C3CF0-4B15-11D1-ABED-709549C10000}
- In HKEY_CLASSES_ROOT\Interface
- {CE7C3CEF-4B15-11D1-ABED-709549C10000}
- {CE7C3CEF-4B15-11D1-ABED-709549C10000}
- In HKEY_CLASSES_ROOT\TypeLib
- {CE7C3CE2-4B15-11D1-ABED-709549C10000}
- {CE7C3CE2-4B15-11D1-ABED-709549C10000}
Step 5
Restore this modified 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\Explorer\Advanced
- From: Hidden = "2"
To: Hidden = "1"
- From: Hidden = "2"
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
- From: ShowSuperHidden = "0"
To: ShowSuperHidden = "1"
- From: ShowSuperHidden = "0"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Advanced\Folder\Hidden\SHOWALL
- From: CheckedValue = "0"
To: CheckedValue = "1"
- From: CheckedValue = "0"
Step 6
Search and delete this file
Step 7
Restart in normal mode and scan your computer with your Trend Micro product for files detected as WORM_AUTORUN.SAC. 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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