root@kali:~# cmp -l info.elf info.elf.2 | gawk '{printf "%08X %02X %02X\n", $1, strtonum(0$2), strtonum(0$3)}'
00000099 55 52
root@kali:~# upx -t info.elf.2 
                       Ultimate Packer for eXecutables
                          Copyright (C) 1996 - 2018
UPX 3.95        Markus Oberhumer, Laszlo Molnar & John Reiser   Aug 26th 2018

testing info.elf.2 
upx: info.elf.2: CantUnpackException: l_info corrupted

Tested 1 file: 0 ok, 1 error.
root@kali:~# upx -t info.elf
                       Ultimate Packer for eXecutables
                          Copyright (C) 1996 - 2018
UPX 3.95        Markus Oberhumer, Laszlo Molnar & John Reiser   Aug 26th 2018

testing info.elf [OK]

Tested 1 file.
root@kali:~# ./info.elf
Enter password:
aaaa
You entered: aaaa
root@kali:~# ./info.elf.2
Enter password:
aaaa
You entered: aaaa