TeleAntiFraud-28k: An Audio-Text Slow-Thinking Dataset for Telecom Fraud Detection

The detection of telecom fraud faces significant challenges due to the lack of high-quality multimodal training data that integrates audio signals with reasoning-oriented textual analysis. To address this gap, we present TeleAntiFraud-28k, the first open-source audio-text slow-thinking dataset specifically designed for automated telecom fraud analysis. Our dataset is constructed through three strategies: (1) Privacy-preserved text-truth sample generation using automatically speech recognition-transcribed call recordings (with anonymized original audio), ensuring real-world consistency through text-to-speech model regeneration; (2) Semantic enhancement via large language model based self-instruction sampling on authentic ASR outputs to expand scenario coverage; (3) Multi-agent adversarial synthesis, which simulates emerging fraud tactics through predefined communication scenarios and fraud typologies, enriches the conversation samples. The generated dataset contains 28,511 rigorously processed audio-text pairs with a total audio duration of more than 307 hours, complete with detailed annotations for fraud reasoning. The dataset is divided into three tasks: scenario classification, fraud detection, fraud type classification. Furthermore, we construct TeleAntiFraud-Bench, a standardized evaluation benchmark comprising proportionally sampled instances from TeleAntiFraud-28k, to facilitate systematic testing of model performance, reasoning capabilities, and thought processes on telecom fraud detection tasks. We also contribute a supervised fine-tuning model based on Qwen2-Audio, trained on the TeleAntiFraud-28k training set, while open-sourcing the data processing framework to enable community-driven dataset expansion. This work establishes a foundational framework for multimodal anti-fraud research while addressing critical challenges in data privacy and scenario diversity. The code of this paper is publicly available at https://github.com/JimmyMa99/TeleAntiFraud.