Starting from w3af 1.0-stable, auto updates are automatically enabled. They
will not work unless you start w3af as root, however there is an optional cron
script to keep the distribution up to date. It is distributed inside the
/usr/doc/w3af-${VERSION} directory and it's called "w3afupdate.sh", there also
is a logrotate config file called "w3afupdate.logrotate" which can be useful.
You should also edit ~/.w3af/startup.conf and set:
  auto-update = false
inside [STARTUP_CONFIG].