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Date discovered:03/01/2006
Type:Backdoor Server
In the wild:No
Reported Infections:Low
Distribution Potential:Low
Damage Potential:Medium
Static file:Yes
File size:32.256 Bytes
MD5 checksum:9dfe1214b9c871893ba6cdf998e686be
VDF version:

 General Method of propagation:
   • No own spreading routine

   •  Mcafee: W32/Dumaru.gen@MM
   •  Kaspersky: Backdoor.Win32.Dumador.fh
   •  Bitdefender: Backdoor.Dumaru.G

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

Side effects:
   • Downloads a file
   • Drops files
   • Drops a malicious file
   • Lowers security settings
   • Registry modification
   • Steals information
   • Third party control

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

The following files are created:

– A file that is for temporary use and it might be deleted afterwards:
   • %WINDIR%\sendlogs_dat
This is a non malicious text file with the following content:
   • %stolen information%

%WINDIR%\dvpd.dll Further investigation pointed out that this file is malware, too. Detected as: BDS/Dumador.EO.2

%WINDIR%\prntc.logc Used to store the clipboard text.
– :\windows\netdx.dat Contains a unique ID of the infected computer.

It tries to download a file:

– The location is the following:
It is saved on the local hard drive under: %WINDIR%\cmdid.dat

 Registry The following registry key is added in order to run the process after reboot:

– [HKLM\Software\Microsoft\Windows\CurrentVersion\Run]
   • "load32" = "%SYSDIR%\winldra.exe"

The following registry keys are added:

– [HKCU\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\
   • "AutoSuggest" = "yes"
   • "Append Completion" = "yes"

– [HKCU\Software\SARS]
   • "SocksPort" = %opened port%
   • "mailsended"="1"

– [HKCU\Software\Microsoft\Internet Explorer\Main]
   • "AllowWindowReuse" = dword:00000000

The following registry key is changed:

– [HKLM\System\CurrentControlSet\Services\SharedAccess]
   Old value:
   • "Start" = %user defined settings%
   New value:
   • "Start" = dword:00000003

 Hosts The host file is modified as explained:

– Access to the following domains is effectively blocked:

The modified host file will look like this:

 Backdoor The following ports are opened:

– iexplore.exe on TCP port 9125 in order to provide backdoor capabilities.
– iexplore.exe on TCP port 11111 in order to provide backdoor capabilities.
– iexplore.exe on a random TCP port in order to provide a Socks 4 proxy server.

Contact server:
All of the following:

As a result it may send information and remote control could be provided. This is done via the HTTP GET and POST method using a PHP script.

Sends information about:
    • Capture screen
    • Created logfiles
    • Current malware status
    • Opened port
    • Platform ID
    • Collected information described in stealing section

Remote control capabilities:
    • Download file
    • Execute file
    • Open remote shell
    • Start keylog
    • Upload file

 Stealing It tries to steal the following information:
– Recorded passwords used by the AutoComplete function
– Email account information obtained from the registry key: HKCU\Software\Microsoft\Internet Account Manager\Accounts

– Passwords from the following programs:
   • The Bat
   • Far
   • Total Commander
   • Webmoney
   • Microsoft Outlook

– A logging routine is started after a website is visited:
   • %any website that contains a login form%
    • Keystrokes
    • Window information
    • Login information

 Injection –  It injects the following file into a process: dvpd.dll

    Process name:
   • iexplore.exe

 File details 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 Daniel Constantin on Thursday, January 5, 2006
Description updated by Andrei Gherman on Monday, January 30, 2006

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