Purpose – This paper aims to investigate the role of forensic accounting skills in enhancing auditor self-efficacy towards fraud detection in Indonesia. In addition, explores the moderating effect of the implementation of Generalized Audit Software (GAS) and whistleblowing system on the relationship between accounting and auditing skills and auditor self-efficacy, as well as its role in enhancing fraud detection. Methodology– A cross-sectional survey was developed and distributed to 537 external auditors working in Indonesia. This study uses a multiple linear regression analysis method with multiple linear moderation models using WarpPLS 8.0 software. Findings – The study results indicate a significant direct relationship between practical communication skills, psychosocial skills, accounting and auditing skills, and auditor self-efficacy. However, technical and analytical factors do not affect auditor self-efficacy. The study's results indicate a significant direct relationship between auditor self-efficacy and fraud detection. It is revealed that implementing GAS moderates the relationship between auditor self-efficacy and fraud detection. In contrast, the study's results do not show a significant relationship between technical and analytical skills and auditor self-efficacy. Novelty– This research paper's originality lies in exploring the role of forensic accounting skills by using GAS and Whistleblowing systems to enhance auditor self-efficacy toward fraud detection in Indonesia.