This achievement seem to be bugged, as it do not pop even after unlocking every safe (5 with codes, 1 with keys). It do seem like they have changed the codes too, as it apparently used to be using different codes.
Codes is as follows, starting af nr 1 (skipping the fourth safe, as it uses the keys)
- 696 818 269 719 129
If anyone have gotten the achievement to pop, after the date i wrote this, please let me know.