6.28. RFB Keywords

The rfb.name and rfb.sectype keywords can be used for matching on various properties of RFB (Remote Framebuffer, i.e. VNC) handshakes.

6.28.1. rfb.name

Match on the value of the RFB desktop name field.

Examples:

rfb.name; content:"Alice's desktop";
rfb.name; pcre:"/.* \(screen [0-9]\)$/";

rfb.name is a ‘sticky buffer’.

rfb.name can be used as fast_pattern.

6.28.2. rfb.secresult

Match on the value of the RFB security result, e.g. ok, fail, toomany or unknown.

Examples:

rfb.secresult: ok;
rfb.secresult: unknown;

6.28.3. rfb.sectype

Match on the value of the RFB security type field, e.g. 2 for VNC challenge-response authentication, 0 for no authentication, and 30 for Apple’s custom Remote Desktop authentication.

This keyword takes a numeric argument after a colon and supports additional qualifiers, such as:

  • > (greater than)
  • < (less than)
  • >= (greater than or equal)
  • <= (less than or equal)

Examples:

rfb.sectype:2;
rfb.sectype:>=3;

6.28.4. Additional information

More information on the protocol can be found here: https://tools.ietf.org/html/rfc6143