WORM_PALEVO.NT
Backdoor:Win32/Zegost.H (Microsoft); Downloader (Symantec); P2P-Worm.Win32.Palevo.coui (Kaspersky); Trojan.Win32.Generic!BT (Sunbelt); Trojan.KillAv.TL (FSecure)
Windows 2000, Windows XP, Windows Server 2003
![](/vinfo/imgFiles/legend.jpg)
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.
Installation
This worm creates the following folders:
- %Program Files%\NamiRobot
(Note: %Program Files% is the default Program Files folder, usually C:\Program Files.)
Autostart Technique
This worm 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\W32Time\TimeProviders\
xyz
Other System Modifications
This worm deletes the following files:
- %Program Files%\MSBuild\Manage.cpl
- %Program Files%\NamiRobot\ResChs.dll
- %System%\WinX86.log
- %System Root%\dll.dll
(Note: %Program Files% is the default Program Files folder, usually C:\Program Files.. %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.. %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\CLSID\{4F7C9975-ECA1-4190-B0EB-E37BC5E40893}\
LocalServer32
It adds the following registry entries:
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\W32Time\TimeProviders\
xyz
DllName = "%Program Files%\NamiRobot\ResChs.dll"
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\W32Time\TimeProviders\
xyz
Enabled = "1"
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\W32Time\TimeProviders\
xyz
InputProvider = "1"
Dropping Routine
This worm drops the following files:
- %User Temp%\kb-155953.tmp
- %User Temp%\kb-158031.tmp
(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003.)
This report is generated via an automated analysis system.
SOLUTION
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 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\W32Time\TimeProviders
- xyz
- In HKEY_CLASSES_ROOT\CLSID\{4F7C9975-ECA1-4190-B0EB-E37BC5E40893}
- LocalServer32
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\SYSTEM\ControlSet001\Services\W32Time\TimeProviders\xyz
- DllName = "%Program Files%\NamiRobot\ResChs.dll"
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\W32Time\TimeProviders\xyz
- Enabled = "1"
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\W32Time\TimeProviders\xyz
- InputProvider = "1"
Step 5
Search and delete these files
- %User Temp%\kb-155953.tmp
- %User Temp%\kb-158031.tmp
Step 6
Search and delete this folder
- %Program Files%\NamiRobot
Step 7
Restart in normal mode and scan your computer with your Trend Micro product for files detected as WORM_PALEVO.NT. 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.
- %Program Files%\MSBuild\Manage.cpl
- %Program Files%\NamiRobot\ResChs.dll
- %System%\WinX86.log
- %System Root%\dll.dll
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