Hack the Box - Sick Teacher Challenge

ctf
challenges
#1

Can you break the cipher?

cat SickTeacher.txt 
KBJICYP CZ KHLTIKWECD

KHLTIKWECD RWMI GBQW JCNW IBNW BM NHP CZ 2017. JBMLW IKWM, BI KHJ FYCRM QWYP VOBLTGP IC IKCOJHMSJ CZ NWNEWYJ ZYCN HGG CQWY IKW FGCEW.
IKW KHGG CZ ZHNW GBJIJ IKW ICA 100 OJWYJ BM CYSWY CZ ACBMIJ. HI IKW IBNW CZ RYBIBMF, IKW ICA 3 OJWYJ HYW JIWZHMC118, ZBGGBACJ HMS HKNWS.
IKWYW HYW JCNW ZCYONJ, H JKCOIECD HMS H JGHLT LKHMMWG. JGHLT HMS JKCOIECD HYW HRWJCNW, EOI IKW ZCYONJ MWWS JCNW GCQW! B RBJK NCYW AWCAGW OJWS IKWN.
KCAWZOGGP IKBJ BJ WMCOFK IWDI IC KWGA RBIK PCOY JOEJIBIOIBCM! FWI LYHLTBM! AJ SCM'I ZCYFWI IC JOAACYI KHLTIKWECD BZ PCO LHM JAHYW JCNW NCMWP. WQWYP AWMMP KWGAJ!

DCDC - HYYWDWG
ZGHF GCYWNBAJONSCGCYJBIHNWI

I searched for Substitution Cipher Solver and found this website: https://www.guballa.de/substitution-solver

HISTORY OF HACKTHEBOX

HACKTHEBOX WENT LIVE SOME TIME IN MAY OF 2017. SINCE THEN, IT HAS GROWN VERY QUICKLY TO THOUSANDS OF MEMBERS FROM ALL OVER THE GLOBE.
THE HALL OF FAME LISTS THE TOP 100 USERS IN ORDER OF POINTS. AT THE TIME OF WRITING, THE TOP 3 USERS ARE STEFANO118, FILLIPOS AND AHMED.
THERE ARE SOME FORUMS, A SHOUTBOX AND A SLACK CHANNEL. SLACK AND SHOUTBOX ARE AWESOME, BUT THE FORUMS NEED SOME LOVE! I WISH MORE PEOPLE USED THEM.
HOPEFULLY THIS IS ENOUGH TEXT TO HELP WITH YOUR SUBSTITUTION! GET CRACKIN! PS DON’T FORGET TO SUPPORT HACKTHEBOX IF YOU CAN SPARE SOME MONEY. EVERY PENNY HELPS!

XOXO - ARREXEL
FLAG LOREMIPSUMDOLORSITAMET