COMB+12billion

In early 2021 and late 2022 massive data aggregations known as Compilation of Many Breaches and 12Billion Special were identified. These databases functioned as large scale combolists containing billions of credentials compiled from thousands of previous leaks and breaches. While the initial raw counts were extremely high researchers identified that after deduplication and filtering for unique entries the core dataset contained approximately 211 million distinct records. The incident represents a significant risk for credential stuffing attacks as it organized many years of historical data into a searchable format for malicious actors.