This challenge looks straight forward, basically we get a file named “file” and the name of the challenge is “I’m a dump” hinting that we should dump something.

A simple file command tells us that the file is a non-stripped Elf binary

$ file file
file: ELF 64-bit LSB pie executable, x86-64, version 1 (SYSV), dynamically linked, interpreter /lib64/ld-linux-x86-64.so.2, BuildID[sha1]=672d1ab79b5c1f063344be7b8edbda2219d8991d, for GNU/Linux 3.2.0, not stripped

Since we should dump something I did a simple strings command on the file and easily enough I found the flag CTFlearn{fla4ggyflag}

$ strings file   
/lib64/ld-linux-x86-64.so.2
libc.so.6
__stack_chk_fail
__cxa_finalize
__libc_start_main
GLIBC_2.2.5
GLIBC_2.4
_ITM_deregisterTMCloneTable
__gmon_start__
_ITM_registerTMCloneTable
u3UH
CTFlearnH
{fl4ggyfH
l4g}H