Take it as a gift :)
Author: z0m31en7
The binary contains base64 encoded strings:
$ strings stringy
[...]
c2VjYXJtH
eXtsMDBrH
X2E3X3RoH
M19zdHIxH
bmc1ISF9H
[...]
Put them together and get the flag.
$ echo "c2VjYXJteXtsMDBrX2E3X3RoM19zdHIxbmc1ISF9" | base64 -d
flag: secarmy{l00k_a7_th3_str1ng5!!}