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Virus:Worm/Yahos.ph
Date discovered:02/02/2011
Type:Worm
In the wild:No
Reported Infections:Low
Distribution Potential:Low to medium
Damage Potential:Low to medium
Static file:Yes
File size:102.400 Bytes
MD5 checksum:74D5BEF03B17C5B9BE3BE54C206D5605
VDF version:7.10.08.106
IVDF version:7.11.02.51 - Wednesday, February 2, 2011

 General Method of propagation:
    Messenger


Aliases:
   •  Kaspersky: IM-Worm.Win32.Yahos.ph
   •  F-Secure: IM-Worm.Win32.Yahos.ph
   •  Sophos: Mal/Rimecud-D
     Norman: W32/Slenfbot.T


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%\ntdll.dl




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: config MsMpSvc start= disabled


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

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

Lower security settings from Internet Explorer:

[HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings\
   ZoneMap]
   New value:
   • "ProxyBypass"=dword:00000001
   • "IntranetName"=dword:00000001
   • "UNCAsIntranet"=dword:00000001

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

[HKEY_CURRENT_CONFIG\Software\Microsoft\windows\CurrentVersion\
   Internet Settings]
   New value:
   • "ProxyEnable"=dword:00000000

 Messenger It is spreading via Messenger. The characteristics are described below:

 Yahoo Messenger


Message
The sent message looks like the following:

   • .m.s|.m.e hahahh Foto :D http://apps.facebook.com/adelbbimg/**********

At the time of analysis the file was not online anymore.

 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!**********
Nickname: NEW-[GBR|00|P|%random numbers%]


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

 Miscellaneous Internet connection:

It queries with the following names:
   • vcs1.msg.yah**********.com
   • vcs2.msg.yah**********.com
   • login.yah**********.com
   • insider.msg.yah**********.com
   • us.dl1.yi**********.com
   • proxy.yospb.yah**********.com
   • voipa.sip.yah**********.com
   • voipb.sip.yah**********.com
   • voipc.sip.yah**********.com
   • de.insider.msg.yah**********.com
   • address.yah**********.com
   • update.messenger.yah**********.com
   • img.msg.yah**********.com
   • de.adserver.yah**********.com
   • beta.stun.voice.yah**********.com
   • l.yi**********.com
   • bs.serving-**********.com
   • row.bc.yah**********.com
   • uk.ard.yah**********.com
   • msgr.updates.yah**********.com
   • ads.yi**********.com
   • uk.adserver.yah**********.com
   • ds.serving-**********.com
   • ad.yieldmanag**********.com
   • yahoo.ivwb**********.de
   • cookex.amp.yah**********.com
   • query.yahooap**********.com
   • content.yieldmanager.edgesu**********.net
   • d.yim**********.com
   • geo.yah**********.com
   • content.yieldmanag**********.com
   • astro.ic.**********.uk
   • ale.pakibi**********.com
   • journalofaccountan**********.com
   • transnationa**********.org
   • mas.0730**********.com
   • api.albertoshisto**********.info
   • stayonti**********.info
   • www.shearm**********.com
   • insidehigher**********.com
   • ate.lacoctele**********.net
   • websitetraffics**********.com
   • qun.5**********.com
   • summer-uni-sw.**********.ch
   • www.facebo**********.com
   • browseusers.myspa**********.com
   • www.myspa**********.com
   • x.myspace**********.com
   • de.data.toolbar.yah**********.com
   • shopsty**********.com
   • xxx.stopklat**********.pl
   • unclef**********.com
   • mcsp.lvengi**********.com
   • ak1.ab**********.net
   • bw.voice.yah**********.com
   • us.i1.yi**********.com
Accesses internet resources:
   • http://browseusers.myspa**********.com/Browse/Browse.aspx
   • http://www.myspa**********.com/browse/people
   • http://www.facebo**********.com/home.php
   • http://www.facebo**********.com/login.php
   • http://174.37.200.**********/config.php

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


Compilation date:
Date: 01/02/2011
Time: 12:34:45

Description inserted by Alexander Bauer on Thursday, February 3, 2011
Description updated by Alexander Bauer on Thursday, February 3, 2011

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