AntiMalware•August 28, 2026•🇷🇺Translated from Russian

Claude AI Agent Accidentally Deletes Developer's 700 GB Home Directory

A developer named Sebastien Guillaime asked an Claude AI agent to write a script that would automatically clean up temporary files created by other AI agents he frequently runs.

Guillaime wanted each agent to operate inside its own isolated sandbox located in /tmp and to have those directories removed after the agent finished its task.

The first version of the script was overly complex and contained multiple destructive deletion commands. Because of these commands, Anthropic's safety system flagged the request as high-risk and automatically downgraded the model, first to Opus 5 and later to Opus 4.8.

The downgraded model created a test that correctly identified both /tmp and the home directory as dangerous locations. However, during the actual cleanup phase it reused the same variable that previously held the path to the user's home folder.

Guillaime stopped the process, but not before 700 GB of data had been deleted. He was able to restore the majority of the information from Git, Nix configuration files, session logs and other backups, yet a full week of work was still lost.

The developer suspects that the forced downgrade to a weaker model increased the chance of the variable conflict being missed, noting that the original Fable 5 model might have detected the error.

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