I heard that you like heaps. It's a high time you proved your skills:
nc ecsc18.hack.cert.pl 10069
Binary: styx.
Libc: libc-2.23.so.
This version of the "Drain waters of Styx" has (hopefully) only the harder solution :).
Format flagi:
ecsc{litery_cyfry_i_znaki_specjalne}
.