Password Cracking Techniques

Password Cracking is the process of recovering passwords from computer systems. It may assist a user in recovering their password, serve as a precautionary step for administrators to verify passwords that are easily broken, or allow an attacker to obtain unauthorised access to the system.

A password is a key piece of information necessary to access a system. Password-cracking attempts are frequently the first step in hacking. An attacker can employ automated tools and tactics, such as a dictionary or brute-force method, or they can manually guess a password and crack it.

Classification of password attacks depends on the attacker's actions, which are of the following four types: 

• Non-Electronic Attacks: An attacker does not need technical knowledge to crack the password, so it is known as a non-technical attack. Techniques include shoulder surfing, social engineering, and dumpster diving.
• Active Online Attacks: The attacker cracks the password by directly communicating with the victim's machine. This is one of the easiest ways to gain unauthorized administrator-level system access. Techniques include password guessing, dictionary and brute-force attacks, hash injection, LLMNR/NBT-NS poisoning, use of Trojans/spyware/keyloggers, internal monologue attacks, Markov-chain attacks, Kerberos password cracking, etc. 
• Passive Online Attacks: The attacker does not have to communicate with the system, but passively monitors or records the data passing over the communication channel, to and from the system.  Techniques include wire sniffing, man-in-the-middle attacks, replay attacks, etc. 
• Offline Attacks: The attacker copies the target's password file and then tries to crack passwords on his own system. Offline attacks are often time-consuming but have a high success rate. Techniques include the Rainbow Table Attack (Pre-Computed Hashes) and the Distributed Network Attack. 

Password Guessing

One method of password cracking is password guessing, which involves manually trying to log in to the target system using several passwords. Using the data gathered by social engineering or any other technique, the attacker generates a list of every potential password and attempts to crack it on the victim's computer. Passwords can be cracked by hackers manually or using automated tools, techniques, and algorithms. 

The following are the steps involved in password guessing:

• Find a valid user
• Create a list of possible passwords
• Rank passwords from high to low probability
• Key in each password, until the correct password is discovered. 

Default Passwords

Manufacturers provide default passwords for new devices (e.g., switches, hubs, routers). Manufacturer-provided default passwords typically let users access the device during initial setup and subsequently change the password. But frequently, an administrator will either disregard the password-change advice or fail to create a new one. Attackers can effectively access the target device by taking advantage of this vulnerability and determining the default password.

The following are some of the online tools to search default passwords:

• open-sez.me
• fortypoundhead.con
• circt.net
• defaultpassword.us
• routerpasswords.com
• default-password.info

Password Recovery Tools

Password recovery tools allow attackers to break complex passwords, recover strong encryption keys, and unlock several documents. Attackers can use these tools to recover the passwords of the target system to gain unauthorized access to critical files and other system software. 

• Elcomsoft Distributed Password Recovery
• Password Recovery Toolkit (accessdata.com)
• hashcat (hashcat.net)
• Windows Password Recovery Tool (windowspasswordsrecovery.com)
• PCUnlocker (top-password.com)

Tools to Extract the Password Hashes

The following tools can be used to extract the password hashes from the target system:

• pwdump7 (tarasco.org)
• Mimikatz (github.com)
• Powershell Empire (github.com)
• DSInternals PowerShell (github.com)
• Ntdsxtract (github.com)

Password-Cracking Tools

You can reset lost or unknown Windows local administrator, domain administrator, and other user account passwords with password-cracking tools. It even gives customers immediate access to their protected computer in the event of a forgotten password without requiring them to reinstall Windows. The target system's passwords can be cracked by attackers using password-cracking software.

• L0phtCrack (l0phtcrack.com)
• ophcrack (ophcrack.sourceforge.net)
• RainbowCrack (project-rainbowcrack.com)
• John the Ripper (openwall.com)
• hashcat (hashcat.net)
• THC-hydra (github.com)
• Medusa (foofus.net)
• CrackStation.net

You might be interested in,

• Phases of Hacking
• Countermeasures for Password Cracking Techniques

We hope this helps. If you have any suggestions or doubts you can add a comment and we will reply as soon as possible.