In cryptanalysis and computer security, a dictionary attack is an attack using a restricted subset of a keyspace to defeat a cipher or authentication mechanism by trying to determine its decryption key or passphrase, sometimes trying thousands or millions of likely possibilities often obtained from lists of past security breaches.
A passphrase is a sequence of words or other text used to control access to a computer system, program or data. It is similar to a password in usage, but a passphrase is generally longer for added security. Passphrases are often used to control both access to, and the operation of, cryptographic programs and systems, especially those that derive an encryption key from a passphrase. The origin of the term is by analogy with password. The modern concept of passphrases is believed to have been invented by Sigmund N. Porter in 1982.
John the Ripper is a free password cracking software tool. Originally developed for the Unix operating system, it can run on fifteen different platforms. It is among the most frequently used password testing and breaking programs as it combines a number of password crackers into one package, automatically detects password hash types, and includes a customizable cracker. It can be run against various encrypted password formats including several crypt password hash types most commonly found on various Unix versions, Kerberos AFS, and Windows NT/2000/XP/2003 LM hash. Additional modules have extended its ability to include MD4-based password hashes and passwords stored in LDAP, MySQL, and others.
In cryptanalysis and computer security, password cracking is the process of guessing passwords protecting a computer system. A common approach is to repeatedly try guesses for the password and to check them against an available cryptographic hash of the password. Another type of approach is password spraying, which is often automated and occurs slowly over time in order to remain undetected, using a list of common passwords.
The Security Account Manager (SAM) is a database file in Windows NT, Windows 2000, Windows XP, Windows Vista, Windows 7, 8.1, 10 and 11 that stores users' passwords. It can be used to authenticate local and remote users. Beginning with Windows 2000 SP4, Active Directory authenticates remote users. SAM uses cryptographic measures to prevent unauthenticated users accessing the system.
Integrated Windows Authentication (IWA) is a term associated with Microsoft products that refers to the SPNEGO, Kerberos, and NTLMSSP authentication protocols with respect to SSPI functionality introduced with Microsoft Windows 2000 and included with later Windows NT-based operating systems. The term is used more commonly for the automatically authenticated connections between Microsoft Internet Information Services, Internet Explorer, and other Active Directory aware applications.
The Encrypting File System (EFS) on Microsoft Windows is a feature introduced in version 3.0 of NTFS that provides filesystem-level encryption. The technology enables files to be transparently encrypted to protect confidential data from attackers with physical access to the computer.
LAN Manager is a discontinued network operating system (NOS) available from multiple vendors and developed by Microsoft in cooperation with 3Com Corporation. It was designed to succeed 3Com's 3+Share network server software which ran atop a heavily modified version of MS-DOS.
MS-CHAP is the Microsoft version of the Challenge-Handshake Authentication Protocol, (CHAP).
A rainbow table is a precomputed table for caching the outputs of a cryptographic hash function, usually for cracking password hashes. Passwords are typically stored not in plain text form, but as hash values. If such a database of hashed passwords falls into the hands of attackers, they can use a precomputed rainbow table to recover the plaintext passwords. A common defense against this attack is to compute the hashes using a key derivation function that adds a "salt" to each password before hashing it, with different passwords receiving different salts, which are stored in plain text along with the hash.
SMBRelay and SMBRelay2 are computer programs that can be used to carry out SMB man-in-the-middle (mitm) attacks on Windows machines. They were written by Sir Dystic of Cult of the Dead Cow (cDc) and released March 21, 2001 at the @lantacon convention in Atlanta, Georgia. More than seven years after its release, Microsoft released a patch that fixed the hole exploited by SMBRelay. This fix only fixes the vulnerability when the SMB is reflected back to the client. If it is forwarded to another host, the vulnerability can be still exploited.
RainbowCrack is a computer program which generates rainbow tables to be used in password cracking. RainbowCrack differs from "conventional" brute force crackers in that it uses large pre-computed tables called rainbow tables to reduce the length of time needed to crack a password drastically. RainbowCrack was developed by Zhu Shuanglei, and implements an improved time–memory tradeoff cryptanalysis attack which originated in Philippe Oechslin's Ophcrack.
In a Windows network, NT LAN Manager (NTLM) is a suite of Microsoft security protocols intended to provide authentication, integrity, and confidentiality to users. NTLM is the successor to the authentication protocol in Microsoft LAN Manager (LANMAN), an older Microsoft product. The NTLM protocol suite is implemented in a Security Support Provider, which combines the LAN Manager authentication protocol, NTLMv1, NTLMv2 and NTLM2 Session protocols in a single package. Whether these protocols are used or can be used on a system, which is governed by Group Policy settings, for which different versions of Windows have different default settings.
Cain and Abel was a password recovery tool for Microsoft Windows. It could recover many kinds of passwords using methods such as network packet sniffing, cracking various password hashes by using methods such as dictionary attacks, brute force and cryptanalysis attacks. Cryptanalysis attacks were done via rainbow tables which could be generated with the winrtgen.exe program provided with Cain and Abel. Cain and Abel was maintained by Massimiliano Montoro and Sean Babcock.
Password strength is a measure of the effectiveness of a password against guessing or brute-force attacks. In its usual form, it estimates how many trials an attacker who does not have direct access to the password would need, on average, to guess it correctly. The strength of a password is a function of length, complexity, and unpredictability.
Crack is a Unix password cracking program designed to allow system administrators to locate users who may have weak passwords vulnerable to a dictionary attack. Crack was the first standalone password cracker for Unix systems and the first to introduce programmable dictionary generation as well.
In computer security, pass the hash is a hacking technique that allows an attacker to authenticate to a remote server or service by using the underlying NTLM or LanMan hash of a user's password, instead of requiring the associated plaintext password as is normally the case. It replaces the need for stealing the plaintext password to gain access with stealing the hash.
crypt is a POSIX C library function. It is typically used to compute the hash of user account passwords. The function outputs a text string which also encodes the salt, and identifies the hash algorithm used. This output string forms a password record, which is usually stored in a text file.
Credential Guard is a virtualization-based isolation technology for LSASS which prevents attackers from stealing credentials that could be used for pass the hash attacks. Credential Guard was introduced with Microsoft's Windows 10 operating system. As of Windows 10 version 20H1, Credential Guard is only available in the Enterprise edition of the operating system.
Q4OS is a light-weight Linux distribution, based on Debian, targeted as a replacement for operating systems that are no longer supported on outdated hardware. The distribution is known for an addon called XPQ4, which adds themes intended to replicate the look and feel of Windows 2000 and Windows XP.
