Rating:
Was it a car or a cat I saw?
file: esab64
Notice that filename is base64 but backwardish. Read file backwards and decode as base64 using tac: tac -r -s 'x\|[^x]' esab64. This produces the flag but backwards so reverse again: tac -r -s 'x\|[^x]' esab64 | base64 -d | tac -r -s 'x\|[^x]' and get the flag
Flag: flag{fb5211b498afe87b1bd0db601117e16e}