"418.6K_PRIVATE_Yahoo.txt" is a database containing approximately 418,600 pairs of compromised Yahoo login credentials, likely derived from the 2013-2014 breaches. These lists are actively used in credential-stuffing attacks to compromise user accounts across various platforms. Immediate action, including updating credentials and enabling two-factor authentication, is recommended for affected users. You can read the full analysis at Have I Been Pwned.
Yahoo Confirms Data Breach of Half a Billion User Accounts - Auth0 418.6K_PRIVATE_Yahoo.txt