Virus:TR/Qhost.N
Date discovered:04/10/2004
Type:Trojan
In the wild:No
Reported Infections:Low
Distribution Potential:Low
Damage Potential:Medium
Static file:Yes
File size:5.632 Bytes
MD5 checksum:5202fa609639e020622d5ad42e21f11a
VDF version:6.27.00.84

 General Method of propagation:
   • No own spreading routine


Aliases:
   •  Symantec: Downloader.Lunii
   •  Mcafee: QHosts-18
   •  Kaspersky: Trojan.Win32.Qhost.n
   •  TrendMicro: TROJ_QHOST.N
   •  Bitdefender: Trojan.Qhost.N


Platforms / OS:
   • Windows 95
   • Windows 98
   • Windows 98 SE
   • Windows NT
   • Windows ME
   • Windows 2000
   • Windows XP
   • Windows 2003


Side effects:
   • Blocks access to certain websites
   • Downloads a file
   • Downloads malicious files
   • Drops a file
   • Registry modification

 Files  It deletes the following files:
   • C:\temp\bdl74125.exe
   • C:\temp\Installer2.exe
   • C:\temp\msbb.exe
   • %SYSDIR%\host32.exe
   • %SYSDIR%\telnet.exe.tmp
   • %SYSDIR%\mouse.exe
   • %SYSDIR%\com.exe
   • %SYSDIR%\fnnmqi.exe
   • %SYSDIR%\exdl.exe
   • %SYSDIR%\exe2bin.exe
   • %SYSDIR%\exul.exe
   • %SYSDIR%\fastopen.exe
   • %SYSDIR%\mscdexnt.exe
   • %SYSDIR%\printer.exe
   • %SYSDIR%\printer32.exe
   • %SYSDIR%\ykyrtws.exe
   • %SYSDIR%\lpt.exe
   • %SYSDIR%\ir.exe
   • %SYSDIR%\intron.exe
   • %SYSDIR%\intronet.exe
   • %SYSDIR%\twink64.exe
   • %SYSDIR%\usb.exe
   • %WINDIR%\alchem.exe
   • %WINDIR%\adp8027_ISEARCHTECH5.exe
   • %WINDIR%\preInsTT.exe
   • %WINDIR%\preInsln.exe
   • %WINDIR%\preInMPP.exe
   • %WINDIR%\loadclean.exe



The following file is created:

– Non malicious file:
   • %WINDIR%\hosts




It tries to download some files:

– The location is the following:
   • http://213.159.117.133/dl/**********
It is saved on the local hard drive under: %WINDIR%\test

– The location is the following:
   • http://213.159.117.133/newprogs/**********
It is saved on the local hard drive under: %WINDIR%\toolbar.exe Furthermore this file gets executed after it was fully downloaded. Further investigation pointed out that this file is malware, too. Detected as: TR/Qhost.N.2


– The location is the following:
   • http://213.159.117.133/newprogs/**********
It is saved on the local hard drive under: %WINDIR%\mstask1.t\exe Furthermore this file gets executed after it was fully downloaded. Further investigation pointed out that this file is malware, too. Detected as: TR/Killav.DB.2

 Registry The values of the following registry key are removed:

–  [HKLM\Software\Microsoft\Windows\CurrentVersion\Run]
   • Ukbybc
   • Tern
   • ControlPanel
   • alchem
   • BullsEye Network
   • dmesewxqtj
   • Internet Optimizer
   • IST Service
   • msbb
   • Power Scan
   • Winad Client



The following registry key including all values and subkeys is removed:
   • [HKLM\Software\Microsoft\Windows\CurrentVersion\Explorer\Browser Helper Objects]

 Hosts The host file is modified as explained:

– In this case existing entries are deleted.

– Access to the following domains is effectively blocked:
   • allforadult.com
   • www.allforadult.com
   • www.iframe.biz
   • iframe.biz
   • www.newiframe.biz
   • newiframe.biz
   • www.vesbiz.biz
   • vesbiz.biz
   • www.pizdato.biz
   • pizdato.biz
   • www.aaasexypics.com
   • aaasexypics.com
   • www.virgin-tgp.net
   • virgin-tgp.net




The modified host file will look like this:


 Process termination List of processes that are terminated:
   • lpt.exe; ir.exe; intron.exe; intronet.exe; twink64.exe; usb.exe;
      teur.exe; host32.exe; sidefind.exe; alchem.exe; powerscan.exe;
      bdl74125.exe; Installer2.exe; ttgkirnl.exe; bargains.exe; WinClt.exe;
      Winad.exe; istsvc.exe; actalert.exe; optimize.exe; iinstall.exe;
      fnnmqi.exe; exdl.exe; printer.exe; printer32.exe; ykyrtws.exe;
      loadclean.exe; telnet.exe


 File details Programming language:
 The malware program was written in MS Visual C++.


Runtime packer:
In order to aggravate detection and reduce size of the file it is packed with the following runtime packer:
   • UPX

Description inserted by Andrei Gherman on Wednesday, April 19, 2006
Description updated by Andrei Gherman on Wednesday, April 19, 2006

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