ARP spoofing, ARP cache poisoning, or ARP poison routing, is a technique by which an attacker sends (spoofed) Address Resolution Protocol (ARP) messages onto a local area network. Generally, the aim is to associate the attacker's MAC address with the IP address of another host, such as the default gateway, causing any traffic meant for that IP address to be sent to the attacker instead.

Source: Wikipedia, May 2017

A backdoor in a computer system, a cryptosystem or an algorithm, is any secret method of bypassing normal authentication or security controls. They may exist for a number of reasons, including by original design or from poor configuration. They may have been added by an authorized party to allow some legitimate access, or by an attacker for malicious reasons; but regardless of the motives for their existence, they create a vulnerability.

Source: Wikipedia, July 2017

An Internet Bot, also known as web robot, WWW robot or simply bot, is a software application that runs automated tasks (scripts) over the Internet. Typically, bots perform tasks that are both simple and structurally repetitive, at a much higher rate than would be possible for a human alone. The largest use of bots is in web spidering (search engine web crawling), in which an automated script fetches, analyzes and files information from web servers at many times the speed of a human.

Another, more malicious use of bots is the coordination and operation of an automated attack on networked computers, such as a denial-of-service attack by a botnet.

Source: Wikipedia, May 2017

A botnet is a number of Internet-connected devices, each of which is running one or more Bots. Botnets can be used to perform Distributed Denial Of Service Attack, steal data, send spam, and allow the attacker access to the device and its connection. The owner can control the botnet using command and control (C&C) software.

Source: Source: Wikipedia, May 2017

A brute-force attack consists of an attacker trying 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.

Source: Wikipedia, May 2017

Buffer overflow, or buffer overrun, is an anomaly where a program, while writing data to a buffer, overruns the buffer's boundary and overwrites adjacent memory locations.

Exploiting the behavior of a buffer overflow is a well-known security exploit. On many systems, the memory layout of a program, or the system as a whole, is well defined. By sending in data designed to cause a buffer overflow, it is possible to write into areas known to hold executable code, and replace it with malicious code. Buffers are widespread in operating system (OS) code, so it is possible to make attacks that perform privilege escalation and gain unlimited access to the computer's resources. The famed Morris worm used this as one of its attack techniques.

Source: Wikipedia, May 2017

A chain of trust is established by validating each component of hardware and software from the bottom up.

A chain of trust is designed to allow multiple users to create and use software on the system, which would be more difficult if all the keys were stored directly in hardware. It starts with hardware that will only boot from software that is digitally signed. The signing authority will only sign boot programs that enforce security, such as only running programs that are themselves signed, or only allowing signed code to have access to certain features of the machine. This process may continue for several layers.

This process results in a chain of trust. The final software can be trusted to have certain properties, because if it had been illegally modified its signature would be invalid, and the previous software would not have executed it. The previous software can be trusted, because it, in turn, would not have been loaded if its signature would have been invalid. The trustworthiness of each layer is guaranteed by the one before, back to the trust anchor.

Source: Wikipedia, May 2017

Clickjacking, also known as "UI redress attack" or "User Interface redress attack", is a malicious technique in which an attacker tricks a user into clicking on a button or link on another webpage while the user intended to click on the top level page. This is done using multiple transparent or opaque layers. The attacker is basically "hijacking" the clicks meant for the top level page and routing them to some other irrelevant page, most likely owned by someone else.

A similar technique can be used to hijack keystrokes. Carefully drafting a combination of stylesheets, iframes, buttons and text boxes, a user can be led into believing that they are typing the password or other information on some authentic webpage while it is being channeled into an invisible frame controlled by the attacker.

Source: Wikipedia, May 2017

Cross-site request forgery, also known as one-click attack or session riding and abbreviated as CSRF (sometimes pronounced sea-surf) or XSRF, is a type of malicious exploit of a website where unauthorized commands are transmitted from a user that the web application trusts. Unlike cross-site scripting (XSS), which exploits the trust a user has for a particular site, CSRF exploits the trust that a site has in a user's browser.

Source: Wikipedia, July 2017

Cross-site scripting (XSS) is a type of computer security vulnerability typically found in web applications. XSS enables attackers to inject client-side scripts into web pages viewed by other users. A cross-site scripting vulnerability may be used by attackers to bypass access controls such as the same-origin policy. Cross-site scripting effect may range from a petty nuisance to a significant security risk, depending on the sensitivity of the data handled by the vulnerable site and the nature of any security mitigation implemented by the site's owner.

Source: Wikipedia, July 2017

A denial-of-service attack (DoS attack) is a cyber-attack where the perpetrator seeks to make a machine or network resource unavailable to its intended users by temporarily or indefinitely disrupting services of a host connected to the Internet. Denial of service is typically accomplished by flooding the targeted machine or resource with superfluous requests in an attempt to overload systems and prevent some or all legitimate requests from being fulfilled.

In a distributed denial-of-service attack (DDoS attack), the incoming traffic flooding the victim originates from many different sources. This effectively makes it impossible to stop the attack simply by blocking a single source. A DoS or DDoS attack is analogous to a group of people crowding the entry door or gate to a shop or business, and not letting legitimate parties enter into the shop or business, disrupting normal operations.

Source: Wikipedia, May 2017

A dictionary attack is a technique for defeating a cipher or authentication mechanism by trying to determine its decryption key or passphrase by trying hundreds or sometimes millions of likely possibilities, such as words in a dictionary.

A dictionary attack is based on trying all the strings in a pre-arranged listing, typically derived from a list of words such as in a dictionary (hence the phrase dictionary attack). In contrast to a brute force attack, where a large proportion of the key space is searched systematically, a dictionary attack tries only those possibilities which are deemed most likely to succeed.

Source: Wikipedia, May 2017

Direct-access attacks are an unauthorized user gaining physical access to a computer is most likely able to directly copy data from it. They may also compromise security by making operating system modifications, installing software worms, keyloggers, covert listening devices or using wireless mice. Even when the system is protected by standard security measures, these may be able to be by-passed by booting another operating system or tool from a CD-ROM or other bootable media. Disk encryption and Trusted Platform Module are designed to prevent these attacks.

Source: Wikipedia, May 2017

Eavesdropping is the act of surreptitiously listening to a private conversation, typically between hosts on a network. For instance, programs such as Carnivore and NarusInsight have been used by the FBI and NSA to eavesdrop on the systems of internet service providers. Even machines that operate as a closed system (i.e., with no contact to the outside world) can be eavesdropped upon via monitoring the faint electro-magnetic transmissions generated by the hardware; TEMPEST is a specification by the NSA referring to these attacks.

Source: Wikipedia, July 2017

A man-in-the-middle attack (MITM, sometimes called a "bucket brigade attack") is an attack where the attacker secretly relays and possibly alters the communication between two parties who believe they are directly communicating with each other.

One example of man-in-the-middle attacks is active eavesdropping, in which the attacker makes independent connections with the victims and relays messages between them to make them believe they are talking directly to each other over a private connection, when in fact the entire conversation is controlled by the attacker. The attacker must be able to intercept all relevant messages passing between the two victims and inject new ones. This is straightforward in many circumstances; for example, an attacker within reception range of wireless access point can insert himself as a man-in-the-middle.

Source: Wikipedia, May 2017

Multi-factor authentication (MFA) is a method of computer access control in which a user is granted access only after successfully presenting several separate pieces of evidence to an authentication mechanism – typically at least two of the following categories: knowledge (something they know), possession (something they have), and inherence (something they are).  Two-factor authentication is a common type of MFA.

Source: Wikipedia, May 2017

In cryptanalysis and 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.

After an attacker obtains valid user name and user password hash values (somehow, using different methods and tools), they are then able to use that information to authenticate to a remote server or service using LM or NTLM authentication without the need to brute-force the hashes to obtain the cleartext password (as it was required before this technique was published). The attack exploits an implementation weakness in the authentication protocol, where password hash remain static from session to session until the password is next changed.

This technique can be performed against any server or service accepting LM or NTLM authentication, whether it runs on a machine with Windows, Unix, or any other operating system.

Source: Wikipedia, July 2017

Pass the ticket (PtT) is a method of authenticating to a system using Kerberos tickets without having access to an account's password. Kerberos authentication can be used as the first step to lateral movement to a remote system.

In this technique, valid Kerberos tickets for Legitimate Credentials are captured by Credential Dumping. A user's service tickets or ticket granting ticket (TGT) may be obtained, depending on the level of access. A service ticket allows for access to a particular resource, whereas a TGT can be used to request service tickets from the Ticket Granting Service (TGS) to access any resource the user has privileges to access.

Silver Tickets can be obtained for services that use Kerberos as an authentication mechanism and are used to generate tickets to access that particular resource and the system that hosts the resource (e.g., SharePoint).

Golden Tickets can be obtained for the domain using the KRBTGT account NTLM hash, which enables generation of TGTs for any account in Active Directory.

Source: Wikipedia, May 2017

Phishing is the attempt to obtain sensitive information such as usernames, passwords, and credit card details (and, indirectly, money), often for malicious reasons, by disguising as a trustworthy entity in an electronic communication.

Phishing is typically carried out by email spoofing or instant messaging and it often directs users to enter personal information at a fake website, the look and feel of which are almost identical to the legitimate one. Communications purporting to be from social web sites, auction sites, banks, online payment processors or IT administrators are often used to lure victims. Phishing emails may contain links to websites that are infected with malware.

Source: Wikipedia, May 2017

Pivoting refers to a method used by penetration testers that uses the compromised system to attack other systems on the same network to avoid restrictions such as firewall configurations, which may prohibit direct access to all machines. For example, if an attacker compromises a web server on a corporate network, the attacker can then use the compromised web server to attack other systems on the network. These types of attacks are often called multi-layered attacks. Pivoting is also known as island hopping.

Pivoting can further be distinguished into proxy pivoting and VPN pivoting. Proxy pivoting generally describes the practice of channeling traffic through a compromised target using a proxy payload on the machine and launching attacks from the computer. This type of pivoting is restricted to certain TCP and UDP ports that are supported by the proxy.

Source: Wikipedia, July 2017

n computer terminology, polymorphic code is code that uses a polymorphic engine to mutate while keeping the original algorithm intact. That is, the code changes itself each time it runs, but the function of the code (its semantics) will not change at all. For example, 1+3 and 6-2 both achieve the same result while using different values and operations. This technique is sometimes used by computer viruses, shellcodes and computer worms to hide their presence.

Encryption is the most common method to hide code. With encryption, the main body of the code (also called its payload) is encrypted and will appear meaningless. For the code to function as before, a decryption function is added to the code. When the code is executed this function reads the payload and decrypts it before executing it in turn. Encryption alone is not polymorphism. To gain polymorphic behavior, the encryptor/decryptor pair are mutated with each copy of the code. This allows different versions of some code which all function the same

Source: Wikipedia 2017

Privilege escalation is the act of exploiting a bug, design flaw or configuration oversight in an operating system or software application to gain elevated access to resources that are normally protected from an application or user. The result is that an application with more privileges than intended by the application developer or system administrator can perform unauthorized actions.

Source: Wikipedia, May 2017

Ransomware is a type of malicious software that blocks access to the victim's data or threatens to publish or delete it until a ransom is paid. Any action is possible once a device or system is infected and there is no guarantee that paying the ransom will return access or not delete or publish the data. Simple ransomware may lock the system in a way which is not difficult for a knowledgeable person to reverse. More advanced malware uses a technique called cryptoviral extortion, in which it encrypts the victim's files, making them inaccessible, and demands a ransom payment to decrypt them. The ransomware may also encrypt the computer's Master File Table (MFT) or the entire hard drive. Thus, ransomware is a Denial-of-Service attack (DoS attack) that prevents computer users from accessing files since it is intractable to decrypt the files without the decryption key. Ransomware attacks are typically carried out using a Trojan that has a payload disguised as a legitimate file.

Source: Wikipedia, July 2017

A rootkit is a collection of computer software, typically malicious, designed to enable access to a computer or areas of its software that would not otherwise be allowed (for example, to an unauthorized user) and often masks its existence or the existence of other software. The term rootkit is a concatenation of "root" (the traditional name of the privileged account on Unix-like operating systems) and the word "kit" (which refers to the software components that implement the tool). The term "rootkit" has negative connotations through its association with malware.

Source: Wikipedia, July 2017

Session hijacking, sometimes also known as cookie hijacking is the exploitation of a valid computer session—sometimes also called a session key—to gain unauthorized access to information or services in a computer system. In particular, it is used to refer to the theft of a magic cookie used to authenticate a user to a remote server. It has particular relevance to web developers, as the HTTP cookies used to maintain a session on many web sites can be easily stolen by an attacker using an intermediary computer or with access to the saved cookies on the victim's computer.

A popular method is using source-routed IP packets. This allows an attacker at point B on the network to participate in a conversation between A and C by encouraging the IP packets to pass through B's machine.

Source: Wikipedia, May 2017

Social engineering, in the context of information security, refers to psychological manipulation of people into performing actions or divulging confidential information. A type of confidence trick for the purpose of information gathering, fraud, or system access, it differs from a traditional "con" in that it is often one of many steps in a more complex fraud scheme.

The term "social engineering" as an act of psychological manipulation is also associated with the social sciences, but its usage has caught on among computer and information security professionals.

Source: Wikipedia, May 2017

Software Defined Perimeter (SDP), also called a "Black Cloud", is an approach to computer security which evolved from the work done at the US Defense Information Systems Agency (DISA) under the Global Information Grid (GIG) Black Core Network initiative around 2007.

Connectivity in a Software Defined Perimeter is based on a need-to-know model, in which device posture and identity are verified before access to application infrastructure is granted. Application infrastructure is effectively “black” (a DoD term meaning the infrastructure cannot be detected), without visible DNS information or IP addresses. The inventors of these systems claim that a Software Defined Perimeter mitigates the most common network-based attacks, including: server scanning, denial of service, SQL injection, operating system and application vulnerability exploits, man-in-the-middle, cross-site scripting (XSS), cross-site request forgery (CSRF), pass-the-hash, pass-the-ticket, and other attacks by unauthorized users.

Source: Wikipedia, May 2017

Spoofing, in general, is a fraudulent or malicious practice in which communication is sent from an unknown source disguised as a source known to the receiver. Spoofing is most prevalent in communication mechanisms that lack a high level of security.

In the context of network security, a spoofing attack is a situation in which one person or program successfully masquerades as another by falsifying data, thereby gaining an illegitimate advantage.

Source: Wikipedia, May 2017

SQL Injection is a code injection technique, used to attack data-driven applications, in which nefarious SQL statements are inserted into an entry field for execution (e.g. to dump the database contents to the attacker).

SQL injection must exploit a security vulnerability in an application's software, for example, when user input is either incorrectly filtered for string literal escape characters embedded in SQL statements or user input is not strongly typed and unexpectedly executed. SQL injection is mostly known as an attack vector for websites but can be used to attack any type of SQL database.

SQL injection attacks allow attackers to spoof identity, tamper with existing data, cause repudiation issues such as voiding transactions or changing balances, allow the complete disclosure of all data on the system, destroy the data or make it otherwise unavailable, and become administrators of the database server.

Source: Wikipedia, July 2017

Trojan horse, or Trojan, is any malicious computer program which is used to hack into a computer by misleading users of its true intent.

Trojans are generally spread by some form of social engineering, for example where a user is duped into executing an e-mail attachment disguised to be unsuspicious, (e.g., a routine form to be filled in), or by drive-by download or from spam links and fake pop up & Advertisement. Although their payload can be anything, many modern forms act as a backdoor, contacting a controller which can then have unauthorized access to the affected computer. This infection allows an attacker to access users' personal information such as banking information, passwords, or personal identity (IP address). Download and install other malware, such as viruses or worms. Unlike computer viruses and worms, Trojans generally do not attempt to inject themselves into other files or otherwise propagate themselves.

Source: Wikipedia, May 2017

Two-factor authentication (also known as 2FA) is a method of confirming a user's claimed identity by utilizing a combination of two different components. Two-factor authentication is a type of multi-factor authentication.

A good example from everyday life is the withdrawing of money from a cash machine; only the correct combination of a bank card (something that the user possesses) and a PIN (personal identification number, something that the user knows) allows the transaction to be carried out. Another example is a login process including a password and a code generated by an independent device.

Source: Wikipedia, May 2017

A computer worm is a standalone malware computer program that replicates itself in order to spread to other computers. Often, it uses a computer network to spread itself, relying on security failures on the target computer to access it. Worms almost always cause at least some harm to the network, even if only by consuming bandwidth, whereas viruses almost always corrupt or modify files on a targeted computer.

Source: Wikipedia, May 2017

A zero-day (also known as zero-hour or 0-day or day zero) vulnerability is an undisclosed computer-software vulnerability that hackers can exploit to adversely affect computer programs, data, additional computers or a network.

It is known as a "zero-day" because it is not publicly reported or announced before becoming active, leaving the software's author with zero days in which to create patches or advise workarounds to mitigate its actions. In effect, zero time has passed since the exploitable bug's existence was disclosed. Similarly, an exploitable bug that has been known for thirty days is sometimes called a 30-day exploit. The fewer the days the bug has been known about, the higher the chances that it has no fix or mitigation.

Source: Wikipedia, July 2017