View Full Version : zip protected files

October 21st, 2001, 18:05

I wonder if it is possible to decrypt a passwordprotected
zip file using softice???

I have tried for many ours without any luck setting different
breakpoint --- tried to patch the zip file......but no luck

I have also tried som of the zip cracker program with bruta
force attack and plaintextattack but no luck
If the password contains many and different characters I believe
it will take loooong time

If this is possible without the real password can someone please give me som hints ???

best regards


October 21st, 2001, 18:26
do some research before asking !!!!

google.com is your start point

watcha waiting ? google.com now

October 21st, 2001, 20:14
No way. Only brute-forcing. That's the answer


October 22nd, 2001, 01:50

thanks for replying

Be shure I have searched a lot at google.com but find
no info on how to decrypt zip protected files without the password.

Okey Solomon the only way is bruta force!!!!!!!!!!!!!!!

Maybe I have missed some good brute force program??

best regards


October 22nd, 2001, 02:54

The program is very fast: for ZIP, brute-force attack speed is up to five million passwords per second on modern CPUs like Pentium II
Guaranteed decryption (usually, within the hour) of most WinZip archives (with 5+ encrypted files) is available; it works regardless the password complexity and length
The program can work with archives containing only one encrypted file

Try it !

October 22nd, 2001, 04:26
thanks sv

I will try it.



October 22nd, 2001, 15:49
geeze, where was this proggy a few years back !!

looks like a little gem.

October 27th, 2001, 19:31
If you know the file was made with WinZIP or NetZip and there are more than five files, my cracker will open it in about 2 hours guaranteed. See

Or you could code your own from the essay I posted on fravia in March.

Is anyone interested in coding one based on the essay? I'm prohibited from distributing my code

(Since I got paid for developing it, it belongs to accessdata)

Did anyone download the copy I linked to a while back? I was told it had to be taken down, but someone must have downloaded it...

October 29th, 2001, 13:05
UrgeOverkill wrote:
>Where was this program a few years ago?

I hadn't written it yet!

I wrote:
>Is anyone interested in coding one based on the essay? I'm
>prohibited from distributing my code
>(Since I got paid for developing it, it belongs to accessdata)

Looks like Elcomsoft did it recently! It's about time...

October 30th, 2001, 00:51
Hello everybody !

The ZIP crypto algorithm may be discussed in the RCE Cryptographics. If someone needs more information about it, download any version of PKZIP for DOS (I'm not sure if it's included in other versions) and read the documentation. It's described there very well.