It can be very difficult to open a ZIP file that is password protected. You need specialized software to figure out the password, and you need a lot of patience while your computer spends hours trying to crack the password. There are many shady websites that exploit this frustration by offering services that would crack the password instantly or for free. Don't fall for that, because these websites spread viruses or adware. It is much safer to use a demo version of a respected program; then you can consider purchasing the program later if you need more features.
Step 1. Understand the risks
You need a program that can crack the password of a ZIP file. Before you do that, you should understand that doing so can infect your computer with a virus. Read this article on how to safely use the Internet and install antivirus software before you get started.
- The programs recommended below have been checked by various automatic malware scans, but safety is not guaranteed.
- Most free demo versions only crack short passwords. Watch out for free programs with no restrictions - normally they don't help a company unless they can install adware or other malware on your computer that way.
Step #2. Assume it will take a long time
In most cases, a program takes several hours to crack a password, unless the password is a single existing word. Passwords with 9 or more characters (that do not form a word) are usually cracked after several days. There is no way to crack a password in minutes.
The only exception is a ZIP archive that contains multiple files protected by the same password, a password you already know. In that case, some programs can run a so-called "known-plaintext" to find out the password, based on the file you already have access to
Step 3. Download a program from Elcomsoft to crack the password
Visit Elcomsoft.com to download the "Advanced Archive Password Recovery" program. Scroll to the bottom of the page and click "Download free trial version". With this free demo version, you can only crack passwords that are four characters or less. The full version costs $49.
If the ZIP file contains two or more files with different passwords, then you need to make multiple copies and delete files in them so that each ZIP archive contains only a single password
Step 4. Try the "ZIP Ultimate Cracker" program
You can download the shareware version here. This program uses some good methods, but with the free version you can only see the first five characters. If that's not long enough to refresh your memory, you can choose to buy the full version for $59, or opt for a one-time use for a lower cost.
This program hasn't been updated in a long time, so updating your operating system might stop the program from working. It is made for Windows 2000, XP, Vista and 7
Step 5. Use "Zip Password Recovery Professional" program
The demo version of this software is free, but with it you can only crack passwords that are smaller than a certain number of characters. Go to this website and click "Download Now" to get started. Open the downloaded file to install the program.
- Programs can use different methods to crack a password. For best results, try each method. These include:
- "Dictionary attack": This method tests a list of words. That's much faster than other methods if it works, but chances are it won't work because many passwords are not existing words.
- Brute force attack: this method tries every possible combination. This only works with short passwords and/or fast processors.
- "Brute force with mask", or "brute force with mask": if you know something about the password, you can report this to the program before the "brute force attack" starts. For example, you can specify that the password contains only letters and not numbers.
- After the file is extracted, the original ZIP archive is still password protected. To remove this protection, create a new ZIP archive of the extracted file by right-clicking it and then selecting "Copy to" → "Compressed Folder".
- A "brute force attack" can take a long time, depending on the speed of your processor. If you want to try this method, consider getting help from people with better computers than yours.
- Copying and downloading licensed software without permission or without paying for it is illegal. It is legal to use software that can crack passwords, but only to access files to which you have the rights.