Fort Knox level account protection here

How do you know which two ISCII characters correspond to it? So I can test this.

I don't really know how Nexon store the passwords (unicode, UTF-8, etc) and if the encode the whole password as unicode or just the letter, so it's hard to say. The hackers, on the other hand, have direct access to the hashes. So in case the unicode characters can really be divided into regular characters, they will find out when they try to crack the hash.

If you can get the 4 digit hex version (eg. U+266C "Beamed Sixteenth Notes": ♬ ) then you look up the UTF-8 conversion chart to go from a U+#### to 1~4 bytes.

In this case, it's in the range U+0800–U+FFFF
(2,048 to 65,535)
Wikipedia provides the conversion to bytes:
1110yyyy 10yyyyxx 10xxxxxx

Since 0x266C is 0010 0110 0110 1100
You end up with
11100010 10011001 10101100
Which in 8-bit (note: ascii characters never start with 1, this is ansi 8840 or something) is characters 226, 153, 172: ♬

So if you go in and tried alt+0226 alt+0153 alt+0172 you should be able to enter the sixteenth note character.

If your password is 12 unicode characters, it's probably not going to work as expected - if Nexon is storing only 12 bytes as the password, it'll just require you to enter the first 12 bytes of your password, if they're hashing the whole thing then there's actually no way to enter your password (except through hash collisions with something under 12 characters).

That's true, but as we all know, protecting against hash collisions never was MD5's strong side.

Isn't it also possible that the hackers can get your birth date through the same exploit?

EDIT: mistakenly wrote ISCII instead of ASCII. Lol.