People rely on technology now more than ever. A person’s most important files—their photos, their projects, their livelihood—can all lie behind a Windows password. But what happens when that password is lost? How do you access that important data? That’s where Ophcrack can help. Ophcrack is a free, open-source program designed to recover lost Windows …
People rely on technology now more than ever. A person’s most important files—their photos, their projects, their livelihood—can all lie behind a Windows password. But what happens when that password is lost? How do you access that important data?
That’s where Ophcrack can help. Ophcrack is a free, open-source program designed to recover lost Windows passwords. Ophcrack can help you crack most passwords, even if using the program requires some technical knowledge. Read on to learn more about this valuable tool.
Pricing is the biggest advantage to using Ophcrack over other popular decryption programs like Kon-Boot or PassFab 4Winkey. While these other programs cost upwards of $20, Ophcrack is totally free. A free download is available on the Ophcrack website and the source code is available online.
Ophcrack additionally requires users to download a “rainbow table,” which is used like a dictionary file to crack passwords. When Ophcrack first started, it required users to pay for rainbow tables for more complex passwords. But since 2019, these tables have been accessible on their website at no charge.
To understand how Ophcrack can recover your lost password, you need to understand how Windows safely stores passwords, and then how those passwords are decrypted.
Ophcrack recovers passwords by decrypting what are known as “password hashes.” Windows keeps track of passwords by turning them into hashes that appear as a string of seemingly random characters. These hashes are stored in the computer’s Security Account Manager (SAM). It takes other free downloadable software, like mimikatz and pwdump8, to find these stored password hashes. Ophcrack then attempts to convert these hashes back into a usable password.
Ophcrack uses “rainbow tables” to guess and eventually find passwords. These virtual tables can contain billions of possible passwords that the program will check based on hashes to identify the correct password.
On the Ophcrack website, you can download a selection of rainbow tables that vary in size and storage space. The smallest rainbow table is just 380 megabytes, but it can only be used to recover passwords that are 14 characters or fewer, without special characters. For more complicated passwords that contain special characters, rainbow tables can range from 8.7 gigabytes to even 2 terabytes at their most comprehensive. Smaller rainbow tables will take less time to decrypt passwords but succeed less often. Larger rainbow tables have a greater success rate but can take hours to run.
The two main ways to use Ophcrack are 1) as a Windows application or 2) as a LiveCD. Using the Windows application takes multiple downloads—one for the application itself, one for a rainbow table, and one for a separate software to extract Windows hashes. This more involved process should yield results for even complicated passwords.
Using the LiveCD version of Ophcrack streamlines this process. Ophcrack can be downloaded onto a flash drive or burned onto a CD via their website. This version of Ophcrack already stores a small rainbow table, and automates the process of extracting hashes from your Windows. The downside of this method is that a LiveCD can only store a small rainbow table, so for passwords that contain special characters this version might be ineffective.
Ophcrack is powerful, but it isn’t easy to use. It requires technical knowledge, like how to extract password hashes from a Windows computer with other downloadable software.
You will need some of this knowledge to navigate the how-to document on the Ophcrack website. They also have a Frequently Asked Questions page and a forum you can browse. Learning beyond these resources will take outside research.
Ophcrack is a legitimate tool designed for users to recover their own lost computer passwords. Even so, decryption software like Ophcrack can be used maliciously by cybercriminals to break into other people’s computers. Hacking a protected computer is a federal crime and violates peoples’ right to privacy.
Ophcrack should only be used for ethical purposes, like recovering your own password, gaining access to old computers, or conducting forensic investigations. You can even use Ophcrack to test the strength of your own passwords and make sure that they are secure against these cybercriminals.
When it comes to password-deciphering programs, Ophcrack stands above the rest for two reasons: 1) It’s effective and 2) It’s free. The program is not intuitive or user-friendly. Using it requires technical knowledge about downloading the right rainbow tables and hash-decrypting software for your situation.
But if recovering a lost password is your main priority and you’re willing to learn, Ophcrack is the most dependable option. It only takes some research and tinkering before you master Ophcrack, making the recovery of lost Windows passwords easy.
