I found this website codeforces.net, and I was about to sign in until I realized the url was different. Is this an official website, or a phishing scam?

I found 22 problems that have the same tag twice.

1910C - Poisonous Swamp
1812E - Not a Geometry Problem
1812B - Was it Rated?
1812A - Are You a Robot?
1790B - Taisia and Dice
1741A - Compare T-Shirt Sizes
1740I - Arranging Crystal Balls
1676C - Most Similar Words
1669C - Odd/Even Increments
1662F - Antennas
1593C - Save More Mice
1593B - Make it Divisible by 25
1531E2 - Сортировка слиянием
1531D - Редактируем Зингер | color
1531B1 - Мониторинг
1490C - Sum of Cubes
1488F - Dogecoin
1466I - The Riddle of the Sphinx
1415B - Repainting Street
1299D - Around the World
1227E - Arson In Berland Forest
676B - Pyramid of Glasses

https://codeforces.com/contest/936/problem/E

https://codeforces.com/contest/1267/problem/C

https://codeforces.com/contest/1912/problem/C

I ran a search and found these 3 problems that don't load in the problemset