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Security Accounts Manager
The Security Account Manager (SAM) is a database file in 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. The user passwords are stored in a hashed format in a registry hive either as an LM hash or as an NTLM hash. This file can be found in %SystemRoot%/system32/config/SAM and is mounted on HKLM/SAM and SYSTEM privileges are required to view it. In an attempt to improve the security of the SAM database against offline software cracking, Microsoft introduced the SYSKEY function in Windows NT 4.0. When SYSKEY is enabled, the on-disk copy of the SAM file is partially encrypted, so that the password hash values for all local accounts stored in the SAM are encrypted with a key (usually also referred to as the "SYSKEY"). It can be enab ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Windows Registry
The Windows Registry is a hierarchical database that stores low-level settings for the Microsoft Windows operating system and for applications that opt to use the registry. The kernel, device drivers, services, Security Accounts Manager, and user interfaces can all use the registry. The registry also allows access to counters for profiling system performance. In other words, the registry or Windows Registry contains information, settings, options, and other values for programs and hardware installed on all versions of Microsoft Windows operating systems. For example, when a program is installed, a new subkey containing settings such as a program's location, its version, and how to start the program, are all added to the Windows Registry. When introduced with Windows 3.1, the Windows Registry primarily stored configuration information for COM-based components. Windows 95 and Windows NT extended its use to rationalize and centralize the information in the profusion of INI files ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
LM Hash
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. History The LAN Manager OS/2 operating system was co-developed by IBM and Microsoft, using the Server Message Block (SMB) protocol. It originally used SMB atop either the NetBIOS Frames (NBF) protocol or a specialized version of the Xerox Network Systems (XNS) protocol. These legacy protocols had been inherited from previous products such as MS-Net for MS-DOS, Xenix-NET for MS-Xenix, and the afore-mentioned 3+Share. A version of LAN Manager for Unix-based systems called LAN Manager/X was also available. Lan Manager/X was the basis for Digital Equipment Corporation's Pathworks product for OpenVMS, Ultrix and Tru64. In 1990, Microsoft announced LAN Manager 2.0 with a host of improvements, including support ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NTLM Hash
In a Windows network, NT (New Technology) 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. NTLM passwords are considered weak because they can be brute-forced very easily with modern hardware. Protocol NTLM is a challenge–response authentication protocol which uses three messages to authenticate a client in a connection-oriented environment (connectionless is similar), and a fourth additional message if integrity i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Syskey
The SAM Lock Tool, better known as Syskey (the name of its executable file), is a discontinued component of Windows NT that encrypts the Security Account Manager (SAM) database using a 128-bit RC4 encryption key. First introduced in the Q143475 hotfix which was included in Windows NT 4.0 SP3, it was removed in Windows 10's Fall Creators Update in 2017 due to its use of cryptography considered unsecure by modern standards, and its use as part of scams as a form of ransomware. Microsoft officially recommended use of BitLocker disk encryption as an alternative. History First introduced in the Q143475 hotfix included in Windows NT 4.0 SP3, Syskey was intended to protect against offline password cracking attacks by preventing the possessor of an unauthorized copy of the SAM file from extracting useful information from it. Syskey can optionally be configured to require the user to enter the key during boot (as a startup password) or load the key onto removable storage media (e.g., a fl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Password Cracking
In cryptanalysis and computer security, password cracking is the process of recovering passwords from data that has been stored in or transmitted by a computer system in scrambled form. A common approach (brute-force attack) 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 purpose of password cracking might be to help a user recover a forgotten password (due to the fact that installing an entirely new password would involve System Administration privileges), to gain unauthorized access to a system, or to act as a preventive measure whereby system administrators check for easily crackable passwords. On a file-by-file basis, password cracking is utilized to gain access to digital evidence to which a judge has allowed access, when a particular fi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ars Technica
''Ars Technica'' is a website covering news and opinions in technology, science, politics, and society, created by Ken Fisher and Jon Stokes in 1998. It publishes news, reviews, and guides on issues such as computer hardware and software, science, technology policy, and video games. ''Ars Technica'' was privately owned until May 2008, when it was sold to Condé Nast Digital, the online division of Condé Nast Publications. Condé Nast purchased the site, along with two others, for $25 million and added it to the company's ''Wired'' Digital group, which also includes ''Wired'' and, formerly, Reddit. The staff mostly works from home and has offices in Boston, Chicago, London, New York City, and San Francisco. The operations of ''Ars Technica'' are funded primarily by advertising, and it has offered a paid subscription service since 2001. History Ken Fisher, who serves as the website's current editor-in-chief, and Jon Stokes created ''Ars Technica'' in 1998. Its purpose was ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pwdump
pwdump is the name of various Windows programs that outputs the LM and NTLM password hashes of local user accounts from the Security Account Manager The Security Account Manager (SAM) is a database file in 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 a ... (SAM) database and from the Active Directory domain's users cache on the operating system. It is widely used, to perform both the famous pass-the-hash attack or also can be used to brute-force users' password directly. In order to work, it must be run under an Administrator account, or be able to access an Administrator account on the computer where the hashes are to be dumped. Pwdump could be said to compromise security because it could allow a malicious administrator to access user's passwords. History The initial program called pwdump was written by Jeremy Allison. He published the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brute-force Attack
In cryptography, a brute-force attack consists of an attacker submitting many passwords or passphrases with the hope of eventually guessing correctly. The attacker systematically checks all possible passwords and passphrases until the correct one is found. Alternatively, the attacker can attempt to guess the key which is typically created from the password using a key derivation function. This is known as an exhaustive key search. A brute-force attack is a cryptanalytic attack that can, in theory, be used to attempt to decrypt any encrypted data (except for data encrypted in an information-theoretically secure manner). Such an attack might be used when it is not possible to take advantage of other weaknesses in an encryption system (if any exist) that would make the task easier. When password-guessing, this method is very fast when used to check all short passwords, but for longer passwords other methods such as the dictionary attack are used because a brute-force search ta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Windows Preinstallation Environment
Windows Preinstallation Environment (also known as Windows PE and WinPE) is a lightweight version of Windows used for the deployment of PCs, workstations, and servers, or troubleshooting an operating system while it is offline. It is intended to replace MS-DOS boot disks and can be booted via USB flash drive, PXE, iPXE, CD-ROM, or hard disk. Traditionally used by large corporations and OEMs (to preinstall Windows client operating systems on PCs during manufacturing), it is now widely available free of charge via Windows Assessment and Deployment Kit (WADK) (formerly Windows Automated Installation Kit (WAIK)). Overview WinPE was originally intended to be used only as a pre-installation platform for deploying Microsoft Windows operating systems, specifically to replace MS-DOS in this respect. WinPE has the following uses: * Deployment of workstations and servers in large corporations as well as pre-installation by system builders of workstations and servers to be sold to end ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chntpw
chntpw is a software utility for resetting or blanking local passwords used by Windows NT, 2000, XP, Vista, 7, 8, 8.1 and 10. It does this by editing the SAM database where Windows stores password hashes. Features There are two ways to use the program: via the standalone ''chntpw'' utility installed as a package available in most modern Linux distributions (e.g. Ubuntu) or via a bootable CD/USB image. There also was a floppy release, but its support has been dropped. Limitations chntpw has no support for fully encrypted NTFS partitions (the only possible exceptions to this are encrypted partitions readable by Linux such as e.g. LUKS), usernames containing Unicode characters, or Active Directory passwords (with the exception of local users of systems that are members of an AD domain). The password changing feature also isn't fully functional either, so password blanking is highly recommended (in fact, for later versions of Windows that's the only possible option). Furth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Passwd
passwd is a command on Unix, Plan 9, Inferno, and most Unix-like operating systems used to change a user's password. The password entered by the user is run through a key derivation function to create a hashed version of the new password, which is saved. Only the hashed version is stored; the entered password is not saved for security reasons. When the user logs on, the password entered by the user during the log on process is run through the same key derivation function and the resulting hashed version is compared with the saved version. If the hashes are identical, the entered password is considered to be correct, and the user is authenticated. In theory, it is possible for two different passwords to produce the same hash. However, cryptographic hash functions are designed in such a way that finding any password that produces the same hash is very difficult and practically infeasible, so if the produced hash matches the stored one, the user can be authenticated. The passwd ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
