Password Cracking Overview The Fundamentals
The process of guessing or recovering a password from stored data is called password cracking. Most of the time, this is accomplished by employing an automated procedure or a dictionary of popular passwords to try to guess the password. Password cracking may occasionally involve exploiting weaknesses in how the password is stored.
Attackers frequently use password cracking to their advantage. Given that it can grant an attacker access to other accounts and systems, it is often the first step in an attack. Additionally, it can be exploited to avoid security precautions like two-factor authentication.
There are numerous techniques for breaking passwords. The most typical method is brute force, where an attacker tries every possible character combination until they find the one that works. Dictionary attacks are another popular technique when an attacker tries popular passwords or terms from a dictionary.
Password cracking can be avoided using strong passwords that are difficult to guess. It’s also crucial to routinely update your passwords and to use unique ones for every account.
Password cracking by exhaustive trial-and-error attacks using brute force
Brute force attacks come in two varieties: those that aim for a particular password and those that attempt every character combination. The former is more prevalent and is frequently used to target high-value accounts, such as those owned by CEOs or famous people. The latter is more computationally costly and is commonly used to break passwords that need better-protected or brute-force encryption systems.
The dictionary assault is the most typical kind of brute force attack. It entails attempting each word on a list of commonly used passwords or in a dictionary as a password. Dictionary assaults are often quite successful, especially when the password is a well-known term or a specific variant of a famous phrase.
The brute-force search is a different kind of brute-force attack. It entails attempting each character combination until the correct password is discovered. Brute-force searches take a long time and are frequently used to break poorly protected passwords or decipher encryption algorithms.
It is incredibly tough to protect against attacks using brute force. The best defense against brute force attacks is a strong and difficult-to-guess password. Using a password that is difficult to brute force is another technique to thwart brute force assaults.
Dictionary Attacks: Using Wordlists and Frequently Used Passwords
A brute force attack that uses a list of words rather than a list of characters is known as a dictionary attack. A dictionary is a list of words that can either be a list of words that are widely used or a list of terms that are connected to the password being cracked.
Dictionary attacks typically fall into one of three categories:
- Wordlist Assaults
- Hybrid assaults
- Attacks based on rules
1. Wordlist Assaults:
The most straightforward and typical kind of dictionary attack is a wordlist assault. It entails utilizing a list of words as passwords and attempting each until the right one is discovered.
The most popular wordlist is the rockyou.txt list, compromised in 2009 and contains 14 million passwords. Other well-known wordlists are the SecLists and the Probable-Wordlists, which are collections of wordlists compiled by the public and the security community, respectively.
2. Hybrid assaults:
A dictionary attack of this kind, known as a “hybrid attack,” combines a wordlist with a list of characters. A word from the wordlist and other characters like symbols or numerals are added.
For instance, if “password1” is the password being cracked, the hybrid attack would test every word in the wordlist before moving on to the numbers 1 through 9. The likelihood of discovering the correct password makes this attack more efficient than a wordlist assault.
3. Rule-based assaults:
A dictionary attack known as a rule-based assault modifies terms in the wordlist using rules. These restrictions can include anything from changing the case of the letters to adding characters to the beginning or end of words.
For instance, the rule-based attack would attempt all the words in the wordlist with the numbers 1–9 at the end of the cracked password as “Password1”. Because it can discover complex passwords, this attack is more efficient than a wordlist assault.
Rainbow Tables: Quick Password Cracking with Precomputed Password Hashes
Passwords can be swiftly cracked using rainbow tables and lists of hashes that have already been computed. When evaluating the security of systems, penetration testers and ethical hackers employ them.
A list of popular passwords is hashed using a cryptographic hash function before creating a rainbow table. After that, a table is created by sorting the hash values. The table is checked for a match when a password needs to be cracked. The relevant password is then obtained if a game is discovered.
Rainbow tables are incredibly efficient at breaking passwords, but their creation can be time- and money-consuming. They need a lot of storage space as well.
Rainbow tables come in a variety of designs, including:
The plaintext passwords utilized to create the hashes are stored in these tables, known as rainbow plaintext tables.
- Hashed rainbow tables: These tables store password hashes rather than the actual passwords.
- Chain rainbow tables: These tables have a series of hashes, beginning with the hash of an existing password and concluding with the hash of the password that needs to be cracked.
A collection of popular passwords, a cryptographic hash function, and a sorting algorithm are required to create a rainbow table.
There are several ways to obtain a list of popular passwords. A password dictionary, which is a list of typical passwords used by penetration testers and ethical hackers, is one method. Use a password generator that generates random passwords that users are likelier to use.
Once you have a list of passwords, you must use a cryptographic hash function to hash each one. Although several alternative hash functions can be utilized, MD5 and SHA-1 are the most widely used.
All of the passwords must be sorted into a table after being hashed. While there are a few other options, the most popular one is to utilize a sorting algorithm. Quicksort and mergesort are two of the most widely used sorting algorithms.
Hybrid Attacks: Using Dictionary and Brute Force for Effectiveness
The act of guessing or retrieving a password from a location where it has been saved or from user-transmitted data is known as password cracking. Most often, brute force or dictionary assaults are used to accomplish this.
In a brute force assault, the attacker attempts every possible character combination in search of the correct password. A dictionary attack is when an attacker attempts each word on a list of words (often words from a dictionary) as a password.
In hybrid assaults, dictionary and brute force methods are combined to increase the likelihood that the correct password will be discovered.
1. Attack with brute force and a mask
This technique employs a mask to reduce the number of passwords that must be attempted. For instance, the show would be “?l?l?l?l?l?l?l?” if the password was known to be eight characters long and only lowercase letters were used. Doing this reduces more than 200 million password combinations to over 4,000.
2. The Hybrid Dictionary Attack using Brute Force
This approach combines a dictionary attack with a brute force attack. The assailant begins by attempting every word in the dictionary. They will then try all character combinations until they locate the correct password if that doesn’t work.
3. Using Dictionary Attack and Rule-Based Password Generation
This technique creates potential passwords from a collection of words using rules. As an illustration, the government “take the first three letters of each word and combine them,” which would result in the passwords “ABC,” “def,” “ghi,” etc.
4. Manipulated Wordlists and Hybrid Dictionary Attack
This approach combines a brute force attack with a dictionary attack. The attacker starts by reversing, adding numerals to the ends of, and using other word manipulation techniques to produce a list of popular terms. The password search will then be conducted using this list. They will then attempt all character combinations until they locate the correct password if that doesn’t work.
Social engineering: coercing users into disclosing passwords
There are numerous ways to breach a password. This blog article concentrates on social engineering, tricking users into revealing passwords.
There are several ways to accomplish this, including:
- Requesting it directly
- Making an imitation login page
- Distributing fraudulent emails
- Using a keylogger
Let’s examine each of these approaches in more detail.
1. Requesting it directly
It is the most straightforward social engineering technique. Ask the user for their password in person or over the phone. Of course, most people won’t just tell a stranger their password. However, they might be more willing to comply if you can establish a connection with them or pose as someone in a position of power.
2. Making an imitation login page
Making a fake login page that resembles the actual one is another typical technique. The user is then duped into providing their username and password on the fictitious website, which you may use to log in to the genuine account. This technique is frequently applied in phishing assaults.
3. Distributing fraudulent emails
Using emails that appear to be from a trustworthy source, like a bank or online merchant, phishing is a social engineering attack. The email will frequently ask recipients to reply with their username and password or provide a link to a false login page.
4. Using a keylogger
A piece of software known as a keylogger captures every keystroke on a keyboard. Passwords can be recorded using this as they are being input. Keyloggers can be placed on their computer without the victim’s knowledge or bought off the shelf.
These are only a few of the most typical social engineering techniques. It’s critical to be aware of the methods criminals can use to steal passwords if you worry they will be hacked.
Seven Phishing Attempted Using Deceptive Methods to Gain User Cred
1. False phishing
The most common sort of phishing attack is deceptive phishing. In a tricky phishing attack, the attacker pretends to be a reliable entity to fool the victim into disclosing personal information, such as passwords or credit card details. The attacker can send an email that appears to be from a reliable organization or build a phony website that looks just like the actual website.
A specific person or business is the target of a spear phishing assault, a sort of phishing attack. The attacker frequently investigates their victim to make their phishing email seem more trustworthy. For instance, they might put the victim’s name or job title in the email.
A spear-phishing whaling attack targets prominent people like CEOs and other top executives. In their email, the attacker will frequently adopt the executive’s character to dupe the victim into disclosing personal information or approving fraudulent transactions.
Vishing is a phishing assault that utilizes text messages or phone calls rather than emails. To deceive the victim into disclosing sensitive information, such as passwords or credit card details, the attacker will frequently assume the identity of a trustworthy business or person.
A vishing assault known as “smishing” uses text messaging rather than phone calls. The attacker would frequently send the victim a text message that appears to be from a trustworthy business or person to deceive them into disclosing personal information.
Pharming is a phishing assault that tricks users into visiting a false website. The attacker can accomplish this by altering a website’s DNS entries or sending a spoof email with a link to the wrong website.
7. Browser exploitation
In a phishing assault known as “browser hijacking,” the victim’s browser settings are changed to drive them to a phony website. Browser exploitation is exploiting vulnerabilities or flaws in web browsers to gain unauthorized access to information, inject malicious code, or engage in other malicious activities.