From the challenge we get N, E, C - Common RSA challenge.

1. On https://factordb.com we can get the factors of N; p & q
2. now on https://www.dcode.fr/rsa-cipher we can input C, E, p & q and decode the RSA to get the flag!
3. Flag: DawgCTF{wh0_n33ds_Q_@nyw@y}

For detailed overview: https://floatingbrij.medium.com/the-obligatory-rsa-challenge-dawgctf-2021-44945de772aa

Original writeup (https://floatingbrij.medium.com/the-obligatory-rsa-challenge-dawgctf-2021-44945de772aa).