Virus:TR/Spy.ZBot.dnv
Date discovered:31/07/2008
Type:Trojan
Subtype:Spy
In the wild:Yes
Reported Infections:Low to medium
Distribution Potential:Low
Damage Potential:Medium
Static file:Yes
File size:60.416 Bytes
MD5 checksum:fa9e2f54724b0af452a91c8dd72814eb
IVDF version:7.00.05.195 - Thursday, July 31, 2008

 General Method of propagation:
   • No own spreading routine


Aliases:
   •  Symantec: Trojan.Wsnpoem
   •  Mcafee: Spy-Agent.bw trojan
   •  Kaspersky: Trojan-Spy.Win32.Zbot.dnv
   •  TrendMicro: TSPY_ZBOT.OJ
   •  F-Secure: Trojan-Spy.Win32.Zbot.dnv
   •  Sophos: Troj/Zbot-AE
   •  Grisoft: Pakes_c_SE
   •  Eset: Win32/Spy.Agent.PZ trojan
   •  Bitdefender: Trojan.Agent.AJKG


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


Side effects:
   • Downloads a malicious file
   • Registry modification
   • Steals information
   • Third party control

 Files It copies itself to the following location:
   • %SYSDIR%\ntos.exe



The following files are created:

– Temporary files that might be deleted afterwards:
   • %SYSDIR%\wnspoem\video.dll
   • %SYSDIR%\wnspoem\audio.dll




It tries to download a file:

– The location is the following:
   • http://66.199.242.115/**********.exe
It is saved on the local hard drive under: %TEMPDIR%\feed.exe Furthermore this file gets executed after it was fully downloaded. Further investigation pointed out that this file is malware, too. Detected as: TR/Drop.Agent.VUF

 Registry The following registry key is changed:

– [HKLM\software\microsoft\windows nt\currentversion\winlogon]
   Old value:
   • "userinit"="%SYSDIR%\userinit.exe,"
   New value:
   • "userinit"="%SYSDIR%\userinit.exe,%SYSDIR%\ntos.exe,"

 Backdoor The following port is opened:

– svchost.exe on a random TCP port


Contact server:
The following:
   • http://ahleinaks.ru/**********millioner.bin

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

 Injection –  It injects the following file into a process: %SYSDIR%\ntos.exe

    Process name:
   • winlogon.exe


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

Description inserted by Andreas Feuerstein on Thursday, July 31, 2008
Description updated by Andreas Feuerstein on Thursday, July 31, 2008

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