The .txt file contains "combo lists" (typically in the format email:password ) that hackers use to gain unauthorized access to premium accounts .
Use services like Have I Been Pwned to see if your email address has appeared in this or other documented data breaches. 1.6M Netflix Targeted UHQ.txt
This file is part of a larger trend where millions of "cracked" Netflix accounts are traded on the dark web. While Netflix itself has not reported a recent infrastructure breach of this scale , these lists represent a major risk for users who do not use unique passwords for every service. 1.6M Netflix Targeted UHQ.txt