Packet Squirrel firmware may be updated via USB as described in the updating firmware article. That said, it is also possible to manually upgrade the firmware by following this process:

  1. Download the latest UPDATE file from https://downloads.hak5.org/squirrel and verify its checksum.
  2. Power on the Packet Squirrel in Arming Mode
  3. Manually SCP the file to the Packet Squirrel’s /tmp directory (e.g. scp upgrade-3.1.bin root@172.16.32.1:/tmp/)
  4. SSH into the Packet Squirrel (e.g. ssh root@172.16.32.1)
  5. From the Packet Squirrel’s bash prompt, issue the sysupgrade command relevant to your firmware update file (e.g. sysupgrade -n /tmp/upgrade-3.1.bin)
  6. Wait 5-10 minutes as the Packet Squirrel flashes the firmware and reboots.