As more companies rely on AI to screen job applications, some applicants are finding ways to game the system through a tactic called prompt injection. A new Duke University study found that at least 1% of 200,000 resumes submitted to the hiring platform hireEZ contained hidden instructions meant to influence AI hiring tools. Prompt injection works by hiding commands inside a resume that people can’t see but AI can. As these tactics spread, applicants might not even know a template they may be using contains prompt injection commands. Researchers say the findings underscore the need for companies who use AI screening tools to identify prompt injection so they can mitigate its impact.