# YARA / Heuristics The `yara` scanner and the accompanying rules act as heuristics detection. Submitted prompts are scanned against the rulesets with matches raised as potential prompt injection. Custom rules can be used by adding them to the `data/yara` directory. ### Default rules * System Instructions * API tokens * IPv4 address * Instruction bypass phrases * Guidance terms --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://vigil.deadbits.ai/overview/use-vigil/scanners/yara-heuristics.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.