Is just that the 56 bit keyspace of DES is feasible to brute force with a few GPU in a short time, so you can brute force they key with a given pair of CryptText and PlainText.
Quote:root@ht:~# echo 1172075784504605 | xxd -r -p | openssl enc -des-ecb -nopad -K $(echo -n hashcat1 | xxd -p) | xxd
00000000: a28b c61d 44bb 815c