WORM_RBOT.EVU
Backdoor:Win32/Rbot.gen!F (Microsoft); W32/Sdbot.worm.gen.g (McAfee); W32.Spybot.Worm (Symantec); PAK:NSPack, Backdoor.Win32.Rbot.adf (Kaspersky); Trojan.Win32.Ircbot!cobra (v) (Sunbelt); Generic.Sdbot.1167367C (FSecure)
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.
Installation
This worm drops the following copies of itself into the affected system:
- %System%\windsp.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_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
Microsoft Display Driver = "windsp.exe"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\RunServices
Microsoft Display Driver = "windsp.exe"
Other System Modifications
This worm adds the following registry keys:
HKEY_LOCAL_MACHINE\Software\Microsoft\
Windows\CurrentVersion\RunServices
HKEY_CURRENT_USER\Software\Microsoft\
OLE
It adds the following registry entries:
HKEY_CURRENT_USER\Software\Microsoft\
OLE
Microsoft Display Driver = "windsp.exe"
It modifies the following registry entries:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Ole
EnableDCOM = "N"
(Note: The default value data of the said registry entry is Y.)
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Control\Lsa
restrictanonymous = "1"
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\Software\Microsoft\Windows\CurrentVersion
- RunServices
- In HKEY_CURRENT_USER\Software\Microsoft
- OLE
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
- Microsoft Display Driver = "windsp.exe"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\RunServices
- Microsoft Display Driver = "windsp.exe"
- In HKEY_CURRENT_USER\Software\Microsoft\OLE
- Microsoft Display Driver = "windsp.exe"
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_LOCAL_MACHINE\SOFTWARE\Microsoft\Ole
- From: EnableDCOM = "N"
To: EnableDCOM = ""Y""
- From: EnableDCOM = "N"
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Control\Lsa
- restrictanonymous = "1"
Step 6
Restart in normal mode and scan your computer with your Trend Micro product for files detected as WORM_RBOT.EVU. 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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