Submission Summary:

• Submission details:
• Submission received: 18 January 2008, 02:45:08
• Processing time: 3 min 27 sec
• Submitted sample:
• File MD5: 0x4450ACCA1864D4CBE5BE3A87F77B433D
• Filesize: 268,288 bytes
• Alias:
• Worm.Hakaglan.B [PCTools]
• W32.Yautoit.N [Symantec]
• IM-Worm.Win32.Sohanad.bm [Kaspersky Lab]
• W32/Cocung.worm [McAfee]
• WORM_IMAUT.E [Trend Micro]

• Summary of the findings:

What's been found	Severity Level
Downloads/requests other files from Internet.
Modifies some system settings that may have negative impact on overall system security state.
Creates a startup registry entry.
Contains characteristics of an identified security risk.

Technical Details:

Possible Security Risk

• Attention! The following threat category was identified:

Threat Category	Description
	A network-aware worm that attempts to replicate across the existing network(s)

File System Modifications

• The following files were created in the system:

#	Filename(s)	File Size	File Hash	Alias
1	%Windir%\RVHOST.exe %System%\RVHOST.exe [file and pathname of the sample #1]	268,288 bytes	MD5: 0x4450ACCA1864D4CBE5BE3A87F77B433D	Worm.Hakaglan.B [PCTools] W32.Yautoit.N [Symantec] IM-Worm.Win32.Sohanad.bm [Kaspersky Lab] W32/Cocung.worm [McAfee] WORM_IMAUT.E [Trend Micro]
2	%Windir%\Tasks\At1.job	346 bytes	MD5: 0x86A382239A9AD304DD0852027BDA8E12	(not available)

• Notes:
• %Windir% is a variable that refers to the Windows installation folder. By default, this is C:\Windows or C:\Winnt.
• %System% is a variable that refers to the System folder. By default, this is C:\Windows\System (Windows 95/98/Me), C:\Winnt\System32 (Windows NT/2000), or C:\Windows\System32 (Windows XP).

Memory Modifications

• There were new processes created in the system:

Process Name	Process Filename	Main Module Size
[filename of the sample #1]	[file and pathname of the sample #1]	655,360 bytes
RVHOST.exe	%System%\rvhost.exe	655,360 bytes

Registry Modifications

• The following Registry Key was created:
• HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\System

• The newly created Registry Values are:
• [HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer]
• NofolderOptions = 0x00000001

to remove the Folder Options item from all Windows Explorer menus and from Control Panel

• [HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\System]
• DisableTaskMgr = 0x00000001
• DisableRegistryTools = 0x00000001

to prevent users from starting Task Manager (Taskmgr.exe)
to disable the Windows registry editors (Regedt32.exe and Regedit.exe)

• [HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run]
• Yahoo Messengger = "%System%\RVHOST.exe"

so that RVHOST.exe runs every time Windows starts

• The following Registry Value was modified:
• [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon]
• Shell = "Explorer.exe RVHOST.exe"

so that RVHOST.exe runs every time Windows starts

Other details

• Analysis of the file resources indicate the following possible country of origin:

	United Kingdom

• The data identified by the following URLs was then requested from the remote web server:
• http://nhatquanglan2.0catch.com/setting.nql
• http://nhatquanglan2.0catch.com/setting.xls
• http://www.freewebs.com/nhattruongquang/setting.nql
• http://www.freewebs.com/nhattruongquang/setting.xls