You are given a electrum wallet file, the wallet is password protected and you have lost both password and initial seed.
With the help of rockyou.txt, BTCRecover and some patience, we are able to recover the password using:
$ python3 btcrecover.py --wallet-type ethereum --wallet wallet --passwordlist rockyou.txt
...
...
Password found: 'julemanden007'
Having found the password, the wallet can be opened using Electrum and in Receive tab we find the flag.
nc3{donation_til_julemandens_wallet}