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Virus:BDS/Hupigon.LQ.1
Date discovered:04/11/2005
Type:Backdoor Server
In the wild:No
Reported Infections:Low
Distribution Potential:Low
Damage Potential:Medium
Static file:Yes
File size:325.632 Bytes
MD5 checksum:c4f0bfa3186d931b86fb025c02443d6d
VDF version:6.32.00.146

 General Aliases:
   •  Symantec: Backdoor.Graybird
   •  Kaspersky: Backdoor.Win32.Hupigon.byu
   •  Sophos: Troj/Hupigo-BYU
   •  Bitdefender: Trojan.NSAnti.A


Platforms / OS:
   • Windows 95
   • Windows 98
   • Windows 98 SE
   • Windows NT
   • Windows ME
   • Windows 2000
   • Windows XP


Side effects:
   • Drops malicious files
   • Registry modification
   • Steals information

 Files It copies itself to the following location:
   • %WINDIR%\rpccall.exe



It deletes the initially executed copy of itself.



It deletes the following files:
   • %SYSDIR%\%six-digit random character string%.sys
   • %WINDIR%\uninstal.bat



The following files are created:

%SYSDIR%\j9u.dll Further investigation pointed out that this file is malware, too. Detected as: BDS/EggDrop.h.1.A

%SYSDIR%\%six-digit random character string%.sys Further investigation pointed out that this file is malware, too. Detected as: TR/Graybird.AA.2

%WINDIR%\rpccall.dll Further investigation pointed out that this file is malware, too. Detected as: TR/Hupigon.GQ.1

%WINDIR%\rpccallKey.DLL Further investigation pointed out that this file is malware, too. Detected as: TR/Hupigon.GQ.1

%WINDIR%\uninstal.bat Furthermore it gets executed after it was fully created. This batch file is used to delete a file.



It tries to download a file:

The location is the following:
   • http://wolforsheep.sitesled.com/gengxin/**********

 Registry The following registry keys are added in order to load the services after reboot:

HKLM\SYSTEM\CurrentControlSet\Services\GOOD05
   • "Type"=dword:00000001
   • "Start"=dword:00000003
   • "ErrorControl"=dword:00000001
   • "ImagePath"="%SYSDIR%\%six-digit random character string%.sys "
   • "DisplayName"="GOOD05"

HKLM\SYSTEM\CurrentControlSet\Services\RPCcallServer
   • "Type"=dword:00000110
   • "Start"=dword:00000002
   • "ErrorControl"=dword:00000000
   • "ImagePath"="%WINDIR%\rpccall.exe"
   • "DisplayName"="RPCcallServer"
   • "ObjectName"="LocalSystem"
   • "Description"="RPCcall Server manager"



The following registry keys are added:

HKLM\SYSTEM\CurrentControlSet\Services\GOOD05\Security
   • "Security"=%hex value%

HKLM\SYSTEM\CurrentControlSet\Services\GOOD05\Enum
   • "0"="Root\\LEGACY_GOOD05\\0000"
   • "Count"=dword:00000001
   • "NextInstance"=dword:00000001

HKLM\SYSTEM\CurrentControlSet\Enum\Root\LEGACY_GOOD05
   • "NextInstance"=dword:00000001

HKLM\SYSTEM\CurrentControlSet\Enum\Root\LEGACY_GOOD05\0000
   • "Service"="GOOD05"
   • "Legacy"=dword:00000001
   • "ConfigFlags"=dword:00000000
   • "Class"="LegacyDriver"
   • "ClassGUID"="{8ECC055D-047F-11D1-A537-0000F8753ED1}"
   • "DeviceDesc"="GOOD05"

HKLM\SYSTEM\CurrentControlSet\Enum\Root\LEGACY_GOOD05\0000\Control
   • "*NewlyCreated*"=dword:00000000
   • "ActiveService"="GOOD05"

HKLM\SYSTEM\CurrentControlSet\Services\RPCcallServer\Security
   • "Security"=%hex value%

HKLM\SYSTEM\CurrentControlSet\Services\RPCcallServer\Enum
   • "0"="Root\\LEGACY_RPCCALLSERVER\\0000"
   • "Count"=dword:00000001
   • "NextInstance"=dword:00000001

HKLM\SYSTEM\CurrentControlSet\Enum\Root\LEGACY_RPCCALLSERVER
   • "NextInstance"=dword:00000001

HKLM\SYSTEM\CurrentControlSet\Enum\Root\LEGACY_RPCCALLSERVER\0000
   • "Service"="RPCcallServer"
   • "Legacy"=dword:00000001
   • "ConfigFlags"=dword:00000000
   • "Class"="LegacyDriver"
   • "ClassGUID"="{8ECC055D-047F-11D1-A537-0000F8753ED1}"
   • "DeviceDesc"="RPCcallServer"

HKLM\SYSTEM\CurrentControlSet\Enum\Root\LEGACY_RPCCALLSERVER\0000\
   Control
   • "*NewlyCreated*"=dword:00000000
   • "ActiveService"="RPCcallServer"

HKLM\SYSTEM\ControlSet001\Control\ServiceCurrent
   • @=dword:0000000c

 Backdoor Contact server:
The following:
   • %URL from downloaded file%

As a result it may send information and remote control could be provided.

 Injection –  It injects the following file into a process: %WINDIR%\rpccallKey.DLL


 It injects a process watching routine into a process.

    All of the following processes:
   • %SYSDIR%\winlogon.exe
   • %WINDIR%\EXPLORER.exe
   • %all processes started after malware is active in memory%


 Rootkit Technology Hides the following:
– Its own files
– Its own processes


Method used:
     Hidden from Windows API

 File details Programming language:
The malware program was written in Delphi.


Runtime packer:
In order to aggravate detection and reduce size of the file it is packed with a runtime packer.

Description inserted by Bogdan Iliuta on Thursday, September 28, 2006
Description updated by Bogdan Iliuta on Wednesday, November 22, 2006

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