Dostoevsky

Prompt Injection Explained: One Practical Demonstration Shows Why It Is Not a Technical Vulnerability

The article demonstrates through direct experiments that prompt injection is not a technical attack but a normal operational behavior of large language models. The author uploaded a PDF containing Dostoevsky text plus hidden instructions to nine AI services and measured how many followed the embedded directives. Two services ignored the instructions entirely, five partially reformatted output, and two fully executed both the list formatting and the persistent account-wide instruction. The same services were then asked to translate the hidden instructions, resulting in eight out of nine interpreting the translation request itself as an executable command. The piece concludes that the only reliable mitigations are explicit user-level rules or service-level refusals, as demonstrated by ChatGPT and Claude.