Fernwartung mal anders

  • Article

In der ISA-Newsgroup bin ich auf einen interessanten Tread gestoßen, in dem UltraVNC SC angerissen wurde. Das ist ein VNC-Viewer mit Bandbreitenoptimierung und Verschlüsselung, der als eine Datei hinterlegt werden kann. Beim Aufruf entpackt er den VNC-Server und startet eine Verbindung zu einem vordefinierten VNC-Viewer beim Supporter, über den dann der Supporter den Client fernsteuern kann.

Das Starten der Verbindung von dem Hilfesuchenden aus vermeidet geschickt die sonst üblichen Firewall-Probleme, da der Supporter oftmals keinen direkten Zugriff auf den Client hat und der Client eventuell wegen einer dynamischen Internetanbindung auch mit wechselnden IP-Adressen arbeitet. Nach dem Ende der Fernwartungsverbindung entfernt sich UltraVNC SC vom Client vollständig. UltraVNC ist auch mit dem Logo der eigenen Firma brandbar.

What is SC?

UltraVNC SC is a mini (166k) UltraVNC Server that can be customized and preconfigured for download by a Customer. UltraVNC SC does not require installation and does not make use of the registry. The customer only have to download the little executable and Click to make a connection. The connection is initiated by the server, to allow easy access thru customers firewall.

What is the difference between UltraVNC and UltraVNC SC?

  • Size: UltraVNC is about 650k while SC is only 166k
  • SC can only do a reverse connection while the normal version server can listen to viewer connections.
  • SC can NOT be run as service, no logon or Ctrl-Alt-Del is supported.
  • SC can only do File Transfers, Directory transfer is not yet supported (but will be soon).
  • SC don't use registry and password. Settings are preconfigured, password is not needed for an outgoing connection.

How secure is UltraVNC SC?

  • The SC version is initiated by the person that shares his desktop: he needs to voluntary click to initiate the connection.
  • You can use up to 128bit encryption. The encryption level depends on the OS and installed MS Crypto api.
  • The server can only connect to the IP adress you have predefined.
  • No incoming connections, no unattended service connection.
  • SC is automatically and systematically uninstalled when the connection is closed.

How to create my own version?

  1. Download custom.zip
  2. Replace the icons ,bmp and rc4.key file with your own version
    Bmp needs to be a windows bitmap, max colors 256, size 196x181 (16colors → smaller size)
    Icons, standard window icons: only 32x32 standard is needed
    The bigger the icons and bmp are, the bigger the final result, the final result is 166k + compressed zip file
    SAME NAMES MUST BE USED… logo.bmp icon1.ico icon2.ic
  3. Replace the rc4.key with your own version or remove the rc4.key if you don't wish to use encryption
    To create your own key you need the normal UltraVnc version and DSM plugin.
    The config button of the DSM plugin allows you to create another key.
    SAME NAMES MUST BE USED… rc4.key
  4. helpdeskt.txt see below
  5. Color background:
    You can add a color background by adding a file background.bmp to the zip file
    Size 1x283, this bmp is stretched as background
  6. Create a zip File from the files you want to customize
    minimum: helpdesk.txt
    maximum: helpdesk.txt rc4.key icon1.ico icon2.ico logo.bmp background.bmp
    MYCOMPANY.zip or jsdgf654324f.zip
    Use somthing unique, else 2 custom versions could get mixed
    DON'T use .(dot) in the name: sample WWW.XXX.zip
  7. Open the UltraVNC SC Creator tool and login:
    Userid: foo
    Password:foobar

Mehr dazu unter UltraVNC SC (SingleClick).