This specific archive is marketed as containing 280,000 sets of credentials that have been verified ("valid") for IMAP/POP3 access. This means the credentials allow a third party to log directly into the victims' email accounts.
Malware designed to steal the credentials of the person downloading the file. 280K VALID MAIL ACCESS.rar
Testing these "valid" credentials against other services (like Netflix, Amazon, or banking portals) where users might reuse the same password. Security Implications This specific archive is marketed as containing 280,000