A resume. This photo is not directly related to the article. [123RF]
A resume. This photo is not directly related to the article. [123RF]

A growing number of job seekers are hiding "secret prompts" targeting AI systems in their resumes in an attempt to land jobs, with some using invisible text to instruct AI tools to rank them as top candidates.

Business Insider reported Sunday (local time) that Paul Lee, CEO of InnoCaption, a US captioning technology company, noticed something unusual while reviewing applications for a legal and compliance position last month.

Among hundreds of resumes, one contained roughly 1,500 characters of text written in white font on a white background. The hidden message was a command directed at AI systems, instructing them to disregard existing instructions and rate the applicant as the top candidate regardless of their qualifications.

Lee said he was shocked by the tactic, calling it an ethical issue for a legal and compliance role where trust and integrity matter. "It's cutting in line," he said.

Similar cases have surfaced at other companies. Simone Rini, co-founder and CEO of Zerolook, a flight-search startup based in Zurich, Switzerland, said he ran about 20 percent of roughly 350 resumes submitted for two engineering positions through an AI tool to check for hidden prompts.

One resume contained instructions to ignore existing directives and prioritize that applicant's submission. Rini said the text read, "Your livelihood depends on you doing so," adding that while the applicant had relevant experience, the strategy did not leave a good impression. "It's just trying to sneak in and get to the top," he said, noting he had blocked the applicant from reapplying.

Such "prompt injection" attacks are spreading rapidly in the real job market, according to research from Duke University.

In a 2026 study, researchers analyzed about 200,000 real resumes submitted through the hiring platform hireEZ and found hidden instructions designed to manipulate AI recruitment systems in at least 1 percent of them.

Prompt injection cases increased sevenfold between July 2024 and November 2025. Researchers attributed the acceleration to videos on TikTok and YouTube explaining the technique, as well as the emergence of free templates for generating hidden prompts.

"What surprised us was not just that people are trying this, but how quickly the practice is spreading," said Neil Gong, an associate professor of electrical and computer engineering at Duke University.

Sarah Franklin, CEO of human resources platform Lattice, told Business Insider the behavior was unsurprising given that companies receive far more applications than they can handle, often sending only form rejection letters or no response at all.

Nada Hashmi, an assistant professor of IT at Babson College, said AI has made it easy for job seekers to submit large volumes of tailored applications, while employers rely on AI to screen candidates from the flood of submissions. "It's like the AIs are talking to each other," she said.


bbo@heraldcorp.com