Colin Pickard has an excellent answer, but there is one 'watch out' with this. There are instances (I haven't figured out the cause yet) where the total length of the "CMG=........GC=...." entry in the file is different from one excel file to the next. In some cases, this entry will be 137 bytes, and in others it will be 143 bytes. The 137 byte length is the odd one, and if this happens when you create your file with the '1234' password, just create another file, and it should jump to the 143 byte length.
I don't know if it is crucial, but I made sure I shut both the hex editor and excel down before reopening the file in Excel. I then had to go through the menus to open the VB Editor, into VBProject Properties and entered in the 'new' password to unlock the code.
Q. Learn How to remove password from excel ?A. In this blog, you will learn how to remove password from excel, but still if you face any issue with the tutorial. You can post your comment with your question on our facebook group. Our Excel Expert will solve your query.
In older versions (below Microsoft Excel 2010), it doesn't even matter how long and complex your password is. Anyone who has at least some basic knowledge of VBA can crack it in minutes (here's an example of the VBA code that easily cracks passwords in Excel 2010 and lower).
Sub PasswordBreaker() 'Breaks worksheet password protection. Dim i As Integer, j As Integer, k As Integer Dim l As Integer, m As Integer, n As Integer Dim i1 As Integer, i2 As Integer, i3 As Integer Dim i4 As Integer, i5 As Integer, i6 As Integer On Error Resume Next For i = 65 To 66: For j = 65 To 66: For k = 65 To 66 For l = 65 To 66: For m = 65 To 66: For i1 = 65 To 66 For i2 = 65 To 66: For i3 = 65 To 66: For i4 = 65 To 66 For i5 = 65 To 66: For i6 = 65 To 66: For n = 32 To 126 ActiveSheet.Unprotect Chr(i) & Chr(j) & Chr(k) & _ Chr(l) & Chr(m) & Chr(i1) & Chr(i2) & Chr(i3) & _ Chr(i4) & Chr(i5) & Chr(i6) & Chr(n) If ActiveSheet.ProtectContents = False Then MsgBox "Password is " & Chr(i) & Chr(j) & _ Chr(k) & Chr(l) & Chr(m) & Chr(i1) & Chr(i2) & _ Chr(i3) & Chr(i4) & Chr(i5) & Chr(i6) & Chr(n) Exit Sub End If Next: Next: Next: Next: Next: Next Next: Next: Next: Next: Next: NextEnd SubPress F5 or click the Run button on the toolbar and wait a couple of minutes.The macro will report a cracked password, which is not the original one (always some combination of A's and B's), but nevertheless it works. You do not need to remember this fake password or enter it anywhere. Simply click OK and the sheet is unprotected!Tips and notes:
There are many password-cracking tools out there, but one of the mainstays has always been John the Ripper. It's a powerful piece of software that can be configured and used in many different ways. Metasploit actually contains a little-known module version of JTR that can be used to quickly crack weak passwords, so let's explore it in an attempt to save precious time and effort.
We can see it starts out by attempting to crack any LM hashes, first in wordlist mode, followed by single-mode, and finally, incremental mode. Next, it follows the same procedure for any NT hashes that are present. Once it completes, it shows us any cracked passwords that it uncovered, along with the associated username:
In this tutorial, we learned about Metasploit's John the Ripper module and how to use it to quickly crack Windows hashes. We first exploited the target using EternalBlue and used the hashdump post module to grab user hashes and store them to the database. Then, we ran the JTR module right in Metasploit and cracked the hash of one of the users. Metasploit's JTR module makes it easy to obtain weak passwords in very little time, and it should be worth a shot in any Windows post-exploitation campaign.
The final step would be to generate random passwords and use a password manager. There are a variety of options including the Chrome built-in Google password manager. If you use a strong password for each site you use, it becomes extremely hard to crack your password.
That's according to a recent study from Hive Systems, a cybersecurity company based in Richmond, Virginia, which breaks down just how long it would likely take the average hacker to crack the passwords safeguarding your most important online accounts.
In a blog post, company researchers explain how the process of cracking your passwords can work. It starts with a process called "hashing," an algorithmically driven process websites use to disguise your stored passwords from hackers.
It's a complicated process, but one that can easily be pulled off by any knowledgeable hacker with consumer-grade equipment, Hive Systems notes. That's why your best defense is using the sort of long, complicated passwords that take the longest to crack.
The report also strongly recommends not recycling passwords for multiple websites. If you do that, and hackers are able to crack your password for one website, then "you're in for a bad time," the company writes.
Understandably, you might not want to remember 18-character passwords each time you log into an online account. After all, a password that takes trillions of years to crack isn't very useful if it also takes you a few million years to remember.
One of the widely used remote online tools used for password-cracking is Brutus. Brutus claims to be the fastest paced and flexible password cracking tool. It is available free of cost and can only be operated in Windows. I t was released in October 2000.
It falls in the hash cracker tool category that utilizes a large-scale time-memory trade off process for faster password cracking compared to traditional brute force tools. Time & memory trade-off is a process of computation where all plain text and hash pairs get calculated by using a chosen hash algorithm. The results are then stored in the rainbow table. This process can be very time-consuming. But, once the table is ready, it is capable of cracking passwords much faster than tools using brute force.
Wfuzz is a web application for password cracking that cracks passwords using brute forcing. It can be used to find hidden resources too like servlets, directories and scripts. This tool is also capable of identifying different kinds of injections with, XSS Injection, LDAP Injection, SQL Injection, etc. in applications of Web.
John the Ripper is yet another popular free open source tool for password cracking in Linux, Mac OS X and Unix. A version for Windows is also available. This tool detects weak passwords. The pro-version of this tool is also available, which offers greater features with native packages for the test of target operating systems.
Medusa is another tool for password cracking like THC Hydra. It is known to be a speedy parallel, login brute forcing tool and modular. When cracking the password; host, password and username can be a flexible input while the performance of the attack.
OphCrack is available for free which is a rainbow-table based tool for password cracking on Windows. It is a popular Windows password cracking tool which can also be used on Linux or Mac. It can crack LM and NTLM hashes. For cracking Windows 7, Vista or Windows XP, free rainbow-tables are made available.
L0phtCrack serves as substitute to OphCrack. It makes various attempts on cracking Windows passwords from hashes. For cracking these passwords, it utilizes the primary controllers of domain, workstations (windows), network server, also Active Directory. It also makes use of dictionary attack and brute force attacking in guessing and generating of passwords. It became an acquisition to Symantec and discontinued in the year 2006. Later developers of L0pht again re-acquired it and launched their L0phtCrack in the year 2009.
Aircrack-NG is a tool for cracking of WiFi passwords that can crack WPA or WEP passwords. It analyses wireless encrypted packets also then tries to crack the passwords with cracking its algorithm. The FMS attack is utilized with other useful attacking methods for cracking of passwords. It is available on Linux and Windows systems. CD of Aircrack is also made available live.
Password cracking tools are however used with various motives, sometimes negative other times, positive. Being aware of such software enlightens the people especially in the information technology and security domain. In the study of information security, such applications are taught with more detail. There are certain applications available to reduce the chances of cyber security attacks through the above mentioned tools and techniques. Whether it is a password for bank account, broking account, social media account or a document password it is ought to be made unbreakable to ensure its utmost security and avoiding unauthorized access. But having mentioned this, the easiest way to guess a password isn't to guess it at all, but to exploit the inherent insecurity in the underlying operating system.
Another major difference between offline and online password attacks is speed. While online password attacks are limited by the speed of the network, offline password attacks are limited only by the speed of the computer the attacker is using to crack them. To put that in context, we have a cracking machine we built for less than $5,000 that can attempt 3 billion password guesses per second. That means that an 8 character password can be brute forced (every possible combination of characters) in less than 3 days.
Once an attacker has extracted the password hashes from the Ntds.dit file, they can use tools like Mimikatz to perform pass-the-hash (PtH) attacks. Furthermore, they can use tools like Hashcat to crack the passwords and obtain their clear text values. Once an attacker has those credentials, there are no limitations on what they can do with them.
John the Ripper is a tool designed to help systems administrators tofind weak (easy to guess or crack through brute force) passwords, andeven automatically mail users warning them about it, if it is desired. 2b1af7f3a8