One of the key tasks in which penetration testers as well as criminals tend to fail is cleaning up after they breach a system. Forensic evidence can be anything from the digital network footprint (the IP address, type of network traffic seen on the wire, and so on) to the logs on a compromised endpoint. There is also evidence of the tools used, such as those used when using a Raspberry Pi to do something malicious. An example is running more ~/.bash_history on a Raspberry Pi to see the entire history of the commands that were used.
The good news for Raspberry Pi hackers is that they don't have to worry about storage elements such as ROM since the only storage to consider is the microSD card. This means attackers just need to re-flash the microSD card to erase evidence that the Raspberry Pi was used. Before doing that, let's work our way through the clean up process starting from the compromised system to the last step of reimaging our Raspberry Pi.