Evidence of Cognitive Biases in Capture-the-Flag Cybersecurity Competitions
Carolina Carreira, Anu Aggarwal, Alejandro Cuevas, Maria José Ferreira, Hanan Hibshi, Cleotilde Gonzalez
TL;DR
This paper investigates how cognitive biases shape attacker decision-making in cybersecurity by analyzing over 525,000 submissions from picoCTF. Using a mixed-methods approach, it identifies signatures of availability bias and the sunk cost fallacy in naturalistic, large-scale data, combining qualitative coding, descriptive statistics, and GLMs. Key findings include a notable share of misformatted-but-correct submissions linked to availability bias and persistence in problem-solving despite declining success probabilities tied to the sunk cost fallacy, with demographic patterns suggesting variation in bias expression. The authors propose a bias-informed defense framework—comprising bias triggers, sensors, and adaptive defenses—to anticipate adversarial actions and guide future experimental integration within CTFs and real systems.
Abstract
Understanding how cognitive biases influence adversarial decision-making is essential for developing effective cyber defenses. Capture-the-Flag (CTF) competitions provide an ecologically valid testbed to study attacker behavior at scale, simulating real-world intrusion scenarios under pressure. We analyze over 500,000 submission logs from picoCTF, a large educational CTF platform, to identify behavioral signatures of cognitive biases with defensive implications. Focusing on availability bias and the sunk cost fallacy, we employ a mixed-methods approach combining qualitative coding, descriptive statistics, and generalized linear modeling. Our findings show that participants often submitted flags with correct content but incorrect formatting (availability bias), and persisted in attempting challenges despite repeated failures and declining success probabilities (sunk cost fallacy). These patterns reveal that biases naturally shape attacker behavior in adversarial contexts. Building on these insights, we outline a framework for bias-informed adaptive defenses that anticipate, rather than simply react to, adversarial actions.
