Machine Learning Attack Series: Backdooring Pickle Files

Pickle files (Python's serialization format for saving objects) can be backdoored because they execute code through opcodes (instructions that control a virtual machine). Attackers can inject malicious commands into pickle files using tools like fickling, and when someone loads the file, the hidden code runs without interrupting the program's normal function. This is especially dangerous in shared environments like Google Colab, where an infected pickle file could give attackers access to a user's connected Google Drive.