Need help? Ask the community or hire an expert.
Go to Avira Answers
Virus:Worm/Yahos.lx
Date discovered:26/01/2011
Type:Worm
In the wild:Yes
Reported Infections:Medium
Distribution Potential:Low
Damage Potential:Medium
Static file:Yes
File size:94.208 Bytes
MD5 checksum:26B84DFB2F3ECBF5DFF168A593F512D9
VDF version:7.10.08.59
IVDF version:7.11.01.251 - Wednesday, January 26, 2011

 General Method of propagation:
   • No own spreading routine


Aliases:
   •  Kaspersky: IM-Worm.Win32.Yahos.lx
   •  F-Secure: IM-Worm.Win32.Yahos.lx
   •  Eset: Win32/Yimfoca.AA worm
   •  DrWeb: Win32.HLLW.Oscar.14


Platforms / OS:
   • Windows 95
   • Windows 98
   • Windows 98 SE
   • Windows ME
   • Windows 2000
   • Windows XP
   • Windows 2003
   • Windows Vista
   • Windows Server 2008
   • Windows 7


Side effects:
   • Drops files
   • Lowers security settings
   • Records keystrokes
   • Registry modification
   • Opens website in web browser

 Files It copies itself to the following location:
   • %WINDIR%\nvsvc32.exe



The following files are created:

– Non malicious files:
   • %WINDIR%\ndl.dl
   • %WINDIR%\wiybr.png
   • %WINDIR%\wibrf.jpg




It tries to execute the following files:

– Filename:
   • %SYSDIR%\net.exe


– Filename:
   • %SYSDIR%\netsh.exe
using the following command line arguments: firewall add allowedprogram 1.exe 1 ENABLE


– Filename:
   • %SYSDIR%\ntvdm.exe
using the following command line arguments: -f -i1


– Filename:
   • %SYSDIR%\ntvdm.exe
using the following command line arguments: -f -i2


– Filename:
   • %SYSDIR%\sc.exe
using the following command line arguments: config wuauserv start= disabled


– Filename:
   • %SYSDIR%\sc.exe
using the following command line arguments: sc config MsMpSvc start= disabled


– Filename:
   • %WINDIR%\explorer.exe
using the following command line arguments: http://browseusers.myspa**********.com/Browse/Browse.aspx

 Registry The following registry keys are added in order to run the processes after reboot:

– [HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run]
   • "NVIDIA driver monitor"="%WINDIR%\\nvsvc32.exe"

– [HKCU\Software\Microsoft\Windows\CurrentVersion\Run]
   • "NVIDIA driver monitor"="%WINDIR%\\nvsvc32.exe"

– [HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Terminal Server\
   Install\Software\Microsoft\Windows\CurrentVersion\Run]
   • "NVIDIA driver monitor"="%WINDIR%\\nvsvc32.exe"



It creates the following entry in order to bypass the Windows XP firewall:

– [HKLM\SYSTEM\ControlSet001\Services\SharedAccess\Parameters\
   FirewallPolicy\StandardProfile\AuthorizedApplications\List]
   • "%malware execution directory%\\%executed
      file%
"="%WINDIR%\\nvsvc32.exe:*:Enabled:NVIDIA driver monitor"



The following registry keys are changed:

Lower security settings from Internet Explorer:

– [HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings\
   ZoneMap]
   Old value:
   • "ProxyBypass"=%user defined settings%
   • "IntranetName"=%user defined settings%
   • "UNCAsIntranet"=%user defined settings%
   New value:
   • "ProxyBypass"=dword:00000001
   • "IntranetName"=dword:00000001
   • "UNCAsIntranet"=dword:00000001

Lower security settings from Internet Explorer:

– [HKCU\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings]
   Old value:
   • "MigrateProxy"=%user defined settings%
   • "ProxyEnable"=%user defined settings%
   • "ProxyServer"=%user defined settings%
   • "ProxyOverride"=%user defined settings%
   • "AutoConfigURL"=%user defined settings%
   New value:
   • "MigrateProxy"=dword:00000001
   • "ProxyEnable"=dword:00000000
   • "ProxyServer"=-
   • "ProxyOverride"=-
   • "AutoConfigURL"=-

Lower security settings from Internet Explorer:

– [HKEY_CURRENT_CONFIG\Software\Microsoft\windows\CurrentVersion\
   Internet Settings]
   Old value:
   • "ProxyEnable"=%user defined settings%
   New value:
   • "ProxyEnable"=dword:00000000

– [HKCR\TypeLib\%CLSID%\1.1\0\win32]
   New value:
   • "(Default)"="oleacc.dll"

 IRC To deliver system information and to provide remote control it connects to the following IRC Server:

Server: %IRC server%
Port: 1234
Server password: xxx
Channel: #!nn! test/mask>
Nickname: NEW-[GBR|00|**********|%random numbers%]


– Furthermore it has the ability to perform actions such as:
    • connect to IRC server
    • disconnect from IRC server
    • Join IRC channel

 Miscellaneous Internet connection:

It queries with the following names:
   • astro.ic.**********.uk
   • ale.pakibiliv.com
   • versatek.com
   • journalofaccountancy.com
   • api.albertoshistory.info
   • journalofaccountancy.com
   • transnationale.org
   • mas.0730ip.com
   • mas.0730ip.com
   • www.facebook.com
   • stayontime.info
   • www.shearman.com
   • insidehighered.com
   • ate.lacoctelera.net
   • websitetrafficspy.com
   • qun.51.com
   • summer-uni-sw.eesp.ch
   • shopstyle.com
   • xxx.stopklatka.pl
   • xxx.stopklatka.pl
   • browseusers.myspace.com
   • www.myspace.com
   • x.myspacecdn.com
Accesses internet resources:
   • http://www.facebo**********.com/home.php;
      http://www.facebo**********.com/login.php;
      http://browseusers.myspa**********.com/Browse/Browse.aspx;
      http://www.myspa**********.com/browse/people;
      http://www.myspa**********.com/help/browserunsupported;
      http://x.myspace**********.com/modules/splash/static/img/cornersSheet.png;
      http://x.myspa**********.com/images/BrowserUpgrade/bg_infobox.jpg;
      http://x.myspa**********.com/images/BrowserUpgrade/icon_information.gif;
      http://x.myspace**********.com/images/BrowserUpgrade/bg_browserSection.jpg;
      http://x.myspace**********.com/images/BrowserUpgrade/browserLogos_med.jpg;
      http://208.43.102.**********/index.php

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


Compilation date:
Date: 25/01/2011
Time: 14:46:52

Description inserted by Alexander Bauer on Thursday, January 27, 2011
Description updated by Alexander Bauer on Thursday, January 27, 2011

Back . . . .