1. Analyze the task’s description.
2. Search the internet using the keywords “plaintext” and “offenders”.
3. Find the site https://plaintextoffenders.com, studying the directories of the site we find https://plaintextoffenders.com/offenders, and in it and https://github.com/plaintextoffenders/plaintextoffenders/blob/master/offenders.csv with a list of domains.The word at the bottom leads to the idea that this is the last of the list of domains, which is the flag.

Flag: VishwaCTF{napcosecurity.com}.