WORM_TATERF.CM
Windows 2000, Windows XP, Windows Server 2003
Threat Type: Worm
Destructiveness: No
Encrypted: No
In the wild: Yes
OVERVIEW
Copies itself in all available physical and removable drives, Propagates via removable drives.
This worm executes then deletes itself afterward.
It modifies registry entries to hide files with System and Read-only attributes.
It drops an AUTORUN.INF file to automatically execute the copies it drops when a user accesses the drives of an affected system.
TECHNICAL DETAILS
106,982 bytes
PE
Yes
02 May 2009
Installation
This worm drops the following component file(s):
- %System%\pytdfse0.dll - also detected as WORM_TATERF.CM
(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%\ierdfgh.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.)
It executes then deletes itself afterward.
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
kxswsoft = "%System%\ierdfgh.exe"
Other System Modifications
This worm modifies the following registry entries to hide files with System and Read-only 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 copies of itself in all physical and removable drives:
- s1.exe
It drops an AUTORUN.INF file to automatically execute the copies it drops when a user accesses the drives of an affected system.
The said .INF file contains the following strings:
[AutoRun]
open=s1.com
shell\open\Command=s1.com
Download Routine
This worm downloads updated copies of itself from the following websites:
- http://{BLOCKED}d.com/xrbv/uu1.rar
SOLUTION
8.900
6.104.22
02 May 2009
5/2/2009 12:00:00 AM
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
- kxswsoft = %System%\ierdfgh.exe
- kxswsoft = %System%\ierdfgh.exe
Step 4
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: 1
- From: Hidden = 2
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
- From: ShowSuperHidden = 0
To: 1
- From: ShowSuperHidden = 0
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Advanced\Folder\Hidden\SHOWALL
- From: CheckedValue = 0
To: 1
- From: CheckedValue = 0
Step 5
Search and delete AUTORUN.INF files created by WORM_TATERF.CM that contain these strings
Step 6
Restart in normal mode and scan your computer with your Trend Micro product for files detected as WORM_TATERF.CM. 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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