We are given `unoriginal` and running file on it yields

```bash
┌──(kali㉿kali)-[~/Desktop]
└─$ file unoriginal
unoriginal: ELF 64-bit LSB pie executable, x86-64, version 1 (SYSV), dynamically linked, interpreter /lib64/ld-linux-x86-64.so.2, BuildID[sha1]=e62dc74b0e909a63a0fc240a62ee75ab47936823, for GNU/Linux 3.2.0, not stripped
```

When running the binary we are prompted to enter a value (assuming it's the flag).

```bash
┌──(kali㉿kali)-[~/Desktop]
└─$ ./unoriginal
Enter your flag here: asdasdasd
Incorrect.
```

Running `strings` on the binary gives us a clue.

```text
┌──(kali㉿kali)-[~/Desktop]
└─$ strings unoriginal
....
Enter your flag here:
lfqc~opvqZdkjqm`wZcidbZfm`fn`wZd6130a0`0``761gdx
Correct!
Incorrect.
.....
```

The idea here is that maybe the string ```lfqc~opvqZdkjqm`wZcidbZfm`fn`wZd6130a0`0``761gdx``` is used in a string comparison and the flag may get printed out. Let's give it a try:

```bash
┌──(kali㉿kali)-[~/Desktop]
└─$ ./unoriginal
Enter your flag here: lfqc~opvqZdkjqm`wZcidbZfm`fn`wZd6130a0`0``761gdx
Incorrect.
```

Time to run the binary through Ghidra. After analysis we find the `main` function and see if we can find our interesting string.

```c
undefined8 main(void)

{
int iVar1;
long in_FS_OFFSET;
int local_4c;
byte local_48 [56];
long local_10;

local_10 = *(long *)(in_FS_OFFSET + 0x28);
printf("Enter your flag here: ");
gets((char *)local_48);
for (local_4c = 0; local_4c < 0x30; local_4c = local_4c + 1) {
local_48[local_4c] = local_48[local_4c] ^ 5;
}
iVar1 = strcmp((char *)local_48,"lfqc~opvqZdkjqm`wZcidbZfm`fn`wZd6130a0`0``761gdx");
if (iVar1 == 0) {
puts("Correct!");
}
else {
puts("Incorrect.");
}
if (local_10 != *(long *)(in_FS_OFFSET + 0x28)) {
/* WARNING: Subroutine does not return */
__stack_chk_fail();
}
return 0;
}
```

From the code above it looks like the flag is being xor'd with the value 5 and then compared with the string we found earlier. A simple python script reverses the value and gets the flag.

```python
inputStr = 'lfqc~opvqZdkjqm`wZcidbZfm`fn`wZd6130a0`0``761gdx'

flag = []
for c in inputStr:
charInt = ord(c)
nextInt = charInt ^ 5
flag.append(chr(nextInt))

print(''.join(flag))
```

FLAG: `ictf{just_another_flag_checker_a3465d5e5ee234ba}`