Most lists are not from a single hack but are aggregations of data from hundreds of previous leaks, deduplicated and normalized into a single file.
Most files follow a predictable user@domain.com:password format, often organized by industry, country, or email provider (e.g., "USA_Gmail_Combo") to help attackers target specific demographics. Download 380K Private User Pass Combo List txt
Unlike raw database dumps that contain metadata (like addresses or phone numbers), combolists are curated specifically for automated attack tools like OpenBullet or Sentry MBA to ingest directly. Most lists are not from a single hack