Sebastian's Blog

software developer. security enthusiast.

HACKVent 2019

HV19.04 password policy circumvention

Sebastian

Santa released a new password policy (more than 40 characters, upper, lower, digit, special).

The elves can’t remember such long passwords, so they found a way to continue to use their old (bad) password:

merry christmas geeks

Challenge Description

Attached to this was the following file named HV19-PPC.ahk

::merry::
FormatTime , x,, MM MMMM yyyy
SendInput, %x%{left 4}{del 2}+{right 2}^c{end}{home}^v{home}V{right 2}{ASC 00123}
return

::christmas::
SendInput HV19-pass-w0rd
return

:*?:is::
Send - {del}{right}4h

:*?:as::
Send {left 8}rmmbr{end}{ASC 00125}{home}{right 10}
return

:*?:ee::
Send {left}{left}{del}{del}{left},{right}e{right}3{right 2}e{right}{del 5}{home}H{right 4}
return

:*?:ks::
Send {del}R3{right}e{right 2}3{right 2} {right 8} {right} the{right 3}t{right} 0f{right 3}{del}c{end}{left 5}{del 4}
return

::xmas::
SendInput, -Hack-Vent-Xmas
return

::geeks::
Send -1337-hack
return

This was an AutoHotkey source file. Loading the script with AutoHotkey, starting Notepad and carefully typing merry christmas geeks (spaces are important!) reveals the flag: HV19{R3memb3r, rem3mber – the 24th 0f December}.

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