You can get the firmware of the Nitrokey Storage here.
An interception would need to be investigated. In such case as simple firmware update may not be sufficient.
The firmware of Nitrokey Pro can't be exported and compared. If you refer to Crypto Stick 1.2 instead, this should be possible by using standard tools (e.g. ST Flash Loader Demonstrator).
You can get the firmware of the Nitrokey Storage here.
An interception would need to be investigated. In such case as simple firmware update may not be sufficient.
The firmware of Nitrokey Pro can't be exported and compared. If you refer to Crypto Stick 1.2 instead, this should be possible by using standard tools (e.g. ST Flash Loader Demonstrator).