zip password crack possible?

Question

I have a piece of software i have to install on company laptops. The installer needs a serial to work properly, but i don't have it (my manager isn't here so i cant ask him). The installer tells me to ring a phone number which doesnt appear to be connected anymore. I would download win32dasm and ollydbg and have a go at cracking the installer but i dont really have time and i havnt done it in years.

There is a zip file on the disc that looks like it contains all the program files but it is passworded. Is it feasible to crack this or will it take ages?

Answer 1

I've cracked some ZIP passwords in a few hours, so i would definitelly give it a try, for example, with ZipCure

Answer 2

As this is old software, it could be that it's using the old version of Winzip encryption - which is very crackable. A Google search will quickly turn something up.

Since Winzip v9, the encryption uses AES, which is secure.

Answer 3

You can use some zip password recovery softwares, but it will take a long time if the password is strong. These programs generally use brute force and you will need a password dictionary for that.

Answer 4

For Linux Users

There is Rarcrack.

Software requirements:
* > glibc 2.4
* any POSIX compatible operating system [sorry Window$ isn't]
* pthreads
* libxml2
* and finally: 7zip, unrar, unzip

Building and installing:

Everything is very easy:

---

tar -xjf rarcrack-VERSION.tar.bz2
cd rarcrack-VERSION
you need gcc or any C compiler (edit Makefile CC=YOUR_C_COMPILER)
make
you must be root in next step:
make install

---

Using RarCrack:

rarcrack your_encrypted_archive.ext [--threads thread_num] [--type rar|zip|7z]

---

Everything in [] are optional, rarcrack default crack two threads and autodetect the archive type. If the detection wrong you can specify the correct file type with the type parameter. RarCrack currently crack maximum in 12 threads.

After the cracking started RarCrack will print the current status of cracking and save it's to a status file. If you want more specific password character set, you need to run RarCrack to create the XML status file (3 sec).

---

<?xml version="1.0" encoding="UTF-8"?>
<rarcrack>
   <abc>0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ</abc>
 <current>uU</current>
 <good_password></good_password>
</rarcrack>

---

This is a sample XML file, and you see there is a character set. If you want, you can modify this file and when you start RarCrack again the program will be use new variables.

Warning: Take care when you changing this file, make sure the current password don't have characters outside the abc[character set]!