How to remove password from a compressed (Zip) file without knowing it

How to remove password from a compressed (Zip) file without knowing it
How to remove password from a compressed (Zip) file without knowing it
Anonim

There may be a day when you have a password protected ZIP archive on your Desktop. To reach the contents of the archive, you will need a program capable of finding the password in question, but it may take several days: you might as well know it in advance!

Steps

Part 1 of 3: Prepare your computer to find a password

Remove the Password from a Zip File Without Knowing the Password Step 1

Step 1. Be aware that there is a risk in this operation

You are going to download a password cracker program. It's not that it's illegal, but on the other hand, it's not legal either. These programs are often the gateway for viruses. First of all, read this article before downloading and installing such a program.

Most often, to bait the customer, the free trial versions are able to find simple passwords (toto38). If on a site you come across a program that is advertised as free and powerful, be careful, there is a risk of downloading malicious program

Remove the Password from a Zip File Without Knowing the Password Step 2

Step 2. Expect to… wait

If the password is short and simple (uniform characters, no particular symbol), count a few hours, otherwise for a long and complex password, count rather several days, even weeks.

There is no program that can find a complex password in a matter of minutes. If it is announced to you as such, you can be sure that it is malware

Remove the Password from a Zip File Without Knowing the Password Step 3

Step 3. Close some programs

As the processor will be heavily used, free up computing power and RAM by closing certain programs, such as photo editors or video games.

Finding a password comes down to doing calculations and even if your computer is equipped with a powerful processor, it takes several days to break a password, even a ZIP archive

Remove the Password from a Zip File Without Knowing the Password Step 4

Step 4. Place your ZIP archive on the Desktop

This is the easiest area to access, as it is a necessary passage point, so it is a good idea before going any further to place your ZIP archive there from the start.

  • To copy and paste the ZIP archive, click on the folder, do the combination Control + C (Windows) or Command + C (Mac), click on the Desktop, then do the combination Control + V or Command + V.
  • First of all, if your ZIP archive is stored on a mobile device (smartphone, tablet), transfer it to your computer.

Part 2 of 3: With John the Ripper

Remove the Password from a Zip File Without Knowing the Password Step 5

Step 1. Understand how this program works

Free, John the Ripper is a program that runs from the command prompt and as the name suggests, it will open something. Its installation and use are delicate.

Remove the Password from a Zip File Without Knowing the Password Step 6

Step 2. Download John the Ripper

Run your Internet browser of choice and go to the John the Ripper download page. Click on one of the links that corresponds to your machine (Windows, Linux, macOS), the choice is made in the first two paragraphs of the page.

Remove the Password from a Zip File Without Knowing the Password Step 7

Step 3. Unzip the John the Ripper file

Simply double click on the ZIP archive, click on the tab Extract, then on Extract all, and finally on Extract: a window will open.

Remove the Password from a Zip File Without Knowing the Password Step 8

Step 4. Install John the Ripper

It does not install like common programs, the best is to install the program folder on your Desktop, remembering to rename it john:

  • in the extraction window that opened, select the john180j1w folder by clicking once on it;
  • press Control + C;
  • open the Desktop, then do Control + V;
  • right click on the folder, then choose Rename;
  • type john, then validate with the Enter key.
Remove the Password from a Zip File Without Knowing the Password Step 9

Step 5. Place your ZIP archive in the run folder

Select it, then copy it using Control + C. Open the john folder, then the run subfolder and paste your archive into it using Control + V.

Remove the Password from a Zip File Without Knowing the Password Step 10

Step 6. Run the command prompt

It allows you to control your computer with very specific commands. For execution, proceed as follows:

  • click on To start up (

    Windowsstart

    );

  • type command prompt;
  • click on Command prompt (

    Windowscmd1

    ), this is the best result at the top of the window.

Remove the Password from a Zip File Without Knowing the Password Step 11

Step 7. Change the name of the John the Ripper run folder

To do this, type

cd desktop / john / run, then validate with Enter.

Remove the Password from a Zip File Without Knowing the Password Step 12

Step 8. Enter the run command

Type

zip2john.exe name.zip> name.hash replacing name with the name of your ZIP archive, then press Enter.

  • If your ZIP archive is called hello, you would type the following command:

    zip2john.exe hello.zip> hello.hash.

Remove the Password from a Zip File Without Knowing the Password Step 13

Step 9. Define the hash of the ZIP archive

Type name.hash (name will of course be replaced by the name of your ZIP archive), then press Enter. Here is ! You are ready to proceed to unlocking the archive.

Remove the Password from a Zip File Without Knowing the Password Step 14

Step 10. Start cracking the password

Type

john.exe --pot = name.pot --wordlist = john / run / password lst name.hash, then press Enter. John the Ripper then searches his database of predefined passwords for the one that could protect your ZIP archive.

  • In this command, you will have to replace name twice with the name of your ZIP archive (name.pot and name.hash).
  • The password lst file contains a list of passwords, along with all their variations (character permutations).
Remove the Password from a Zip File Without Knowing the Password Step 15

Step 11. Control the display of the password

Once the password is determined, you will see The session ended successfully on the last line of the prompt. Then type type name.pot (replace name with the name of your archive), then press Enter and the password for the ZIP archive should appear.

Part 3 of 3: With paid software

Remove the Password from a Zip File Without Knowing the Password Step 16

Step 1. Understand how this software works

These paid software have a free part to find simple passwords, but when it comes to finding more complicated passwords, the software becomes, and it makes sense, paid.

On the other hand, let's recognize that their handling is quite easy and the interface user-friendly

Remove the Password from a Zip File Without Knowing the Password Step 17

Step 2. Don't go for just any software

Yours must have a trial version and must be able to use one of the brute force techniques.

Remove the Password from a Zip File Without Knowing the Password Step 18

Step 3. Download professional password recovery software

The ones we show you are all chargeable, but they are among the best on the market. It is:

  • Advanced Archive Password Recovery at:
  • Zip Password Recovery Professional at:

    download.cnet.com/ZIP-Password-Recovery-Professional/3000-18501_4-75031119.html;

  • ZipKey at:
Remove the Password from a Zip File Without Knowing the Password Step 19

Step 4. Run the password recovery software

Like any software, execution is done by clicking or double-clicking on the software icon.

Remove the Password from a Zip File Without Knowing the Password Step 20

Step 5. Select your password protected ZIP archive

Depending on the software, click a button Browse Where Add, click on the ZIP archive, then on a button To open Where To choose.

Often, too, it is possible to take the archive to be unlocked with the mouse and drop it on the main window of the software

Remove the Password from a Zip File Without Knowing the Password Step 21

Step 6. Choose one of the three or four principles of recovery

For the more sophisticated of them, you have the choice between the attack (that's what this recovery is called!) By brute force, by dictionary, by mask or by simple text.

The dictionary, which can be configured, is used in cases where you know some elements of the password or if you know it entirely, with the exception of the particular characters (&, #, @) or the case used (lowercase or uppercase)

Remove the Password from a Zip File Without Knowing the Password Step 22

Step 7. Start the password search

Just click the button Start (To start up) Where Run (Execute) of your application, then all you have to do is wait. We said it: it can take days!

Remove the Password from a Zip File Without Knowing the Password Step 23

Step 8. Recover password from ZIP archive

Hoping that it has been found, you will see a mention appear inviting you to discover it. You just have to test it by launching the decompression of the archive.

Advice

  • Serious software always gives you a search option, then another if the first one fails. There are three search methods.

    • The dictionary attack is based on testing thousands of predefined passwords in a dictionary. If the password is complex, it may not be there.
    • The brute force attack is based on the combination test. It is useful for short passwords with a fast processor.
    • The brute force mask attack is useful if you have some information in advance about the password, for example, that it contains only lowercase letters or only numbers.
  • Expect to let your computer run for several days before the program discovers the password.

Warnings

  • The duration of a successful brute force attack depends on the power of your computer. The calculations are certainly simple, but the machine is very strained and after a certain time, the processor may even lay down its weapons.
  • These password recovery software are legal, nothing prevents you from using them for honest purposes.
  • Downloading, modifying and using software without the agreement of its designer often falls, and this is the case in France, under the law.

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