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Virus:Worm/Yahos.lr
Date discovered:25/01/2011
Type:Worm
In the wild:Yes
Reported Infections:Low
Distribution Potential:Low
Damage Potential:Medium
Static file:Yes
File size:94.208 Bytes
MD5 checksum:9CBB143AB81600DC0D2868F19A3B8593
VDF version:7.10.08.46
IVDF version:7.11.01.238 - Tuesday, January 25, 2011

 General Method of propagation:
   • No own spreading routine


Aliases:
   •  Mcafee: Artemis!9CBB143AB816
   •  Kaspersky: IM-Worm.Win32.Yahos.lr
   •  F-Secure: IM-Worm.Win32.Yahos.lr
   •  Microsoft: Worm:Win32/Slenfbot.AKD
   •  Eset: IRC/SdBot
   •  Rising: Backdoor.Win32.Undef.ssy


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 a file
   • 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 file is created:

– Non malicious file:
   • %WINDIR%\wiybr.png




It tries to execute the following files:

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


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


– 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: config MsMpSvc start= disabled

 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

– [HKCR\TypeLib\{1EA4DBF0-3C3B-11CF-810C-00AA00389B71}\1.1\0\win32]
   New value:
   • "(Default)"="%SYSDIR%\\oleacc.dll"

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

Server: %IRC server%
Port: 1234
Channel: #!nn**********
Nickname: NEW-[GBR|00|P|**********]
Password: xxx


– 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.pakibi**********.com
   • versat**********.com
   • journalofaccounta**********.com
   • transnationa**********.org
   • mas.0730**********.com
   • api.albertoshist**********.info
   • stayonti**********.info
   • www.shearm**********.com
   • insidehigher**********.com
   • ate.lacoctele**********.net
   • websitetraffic**********.com
   • www.facebo**********.com
   • browseusers.myspa**********.com
   • www.myspa**********.com
   • x.myspace**********.com
   • qun.5**********.com
   • summer-uni-sw.**********.ch
   • shopsty**********.com
   • xxx.stopklat**********.pl
   • unclef**********.com
   • mcsp.lvengi**********.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/images/BrowserUpgrade/bg_infobox.jpg;
      http://x.myspace**********..com/modules/splash/static/img/cornersSheet.png;
      http://x.myspace**********..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://174.37.200.**********./index.php

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


Compilation date:
Date: 24/01/2011
Time: 20:45:49

Description inserted by Alexander Bauer on Wednesday, January 26, 2011
Description updated by Alexander Bauer on Wednesday, January 26, 2011

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