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DMARC
Domain-based Message Authentication, Reporting and Conformance (DMARC) is an email authentication protocol. It is designed to give email domain owners the ability to protect their domain from unauthorized use, commonly known as email spoofing. The purpose and primary outcome of implementing DMARC is to protect a domain from being used in business email compromise attacks, phishing email, email scams and other cyber threat activities. Once the DMARC DNS entry is published, any receiving email server can authenticate the incoming email based on the instructions published by the domain owner within the DNS entry. If the email passes the authentication, it will be delivered and can be trusted. If the email fails the check, depending on the instructions held within the DMARC record the email could be delivered, quarantined or rejected. For example, one email forwarding service delivers the mail, but as "From: no-reply@". DMARC extends two existing email authentication mechanisms, Se ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DomainKeys Identified Mail
DomainKeys Identified Mail (DKIM) is an email authentication method designed to detect forged sender addresses in email (email spoofing), a technique often used in phishing and email spam. DKIM allows the receiver to check that an email claimed to have come from a specific domain was indeed authorized by the owner of that domain. It achieves this by affixing a digital signature, linked to a domain name, to each outgoing email message. The recipient system can verify this by looking up the sender's public key published in the DNS. A valid signature also guarantees that some parts of the email (possibly including attachments) have not been modified since the signature was affixed. Usually, DKIM signatures are not visible to end-users, and are affixed or verified by the infrastructure rather than the message's authors and recipients. DKIM is an Internet Standard. It is defined in RFC 6376, dated September 2011; with updates in RFC 8301 and RFC 8463. Overview The need for e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sender Policy Framework
Sender Policy Framework (SPF) is an email authentication method designed to detect forging sender addresses during the delivery of the email. SPF alone, though, is limited to detecting a forged sender claim in the envelope of the email, which is used when the mail gets bounced. Only in combination with DMARC can it be used to detect the forging of the visible sender in emails (email spoofing), a technique often used in phishing and email spam. SPF allows the receiving mail server to check during mail delivery that a mail claiming to come from a specific domain is submitted by an IP address authorized by that domain's administrators. The list of authorized sending hosts and IP addresses for a domain is published in the DNS records for that domain. Sender Policy Framework is defined in RFC 7208 dated April 2014 as a "proposed standard". History The first public mention of the concept was in 2000 but went mostly unnoticed. No mention was made of the concept again until a first att ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Email Authentication
Email authentication, or validation, is a collection of techniques aimed at providing verifiable information about the origin of email messages by validating the domain ownership of any message transfer agents (MTA) who participated in transferring and possibly modifying a message. The original base of Internet email, Simple Mail Transfer Protocol (SMTP), has no such feature, so forged sender addresses in emails (a practice known as email spoofing) have been widely used in phishing, email spam, and various types of fraud. To combat this, many competing email authentication proposals have been developed, but only fairly recently have three been widely adopted – SPF, DKIM and DMARC. The results of such validation can be used in automated email filtering, or can assist recipients when selecting an appropriate action. This article does not cover user authentication of email submission and retrieval. Rationale In the early 1980s, when Simple Mail Transfer Protocol (SMTP) was design ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TXT Record
A TXT record (short for text record) is a type of resource record in the Domain name system (DNS) used to provide the ability to associate arbitrary text with a host or other name, such as human readable information about a server, network, data center, or other accounting information. It is also often used in a more structured fashion to record small amounts of machine-readable data into the DNS. Background A domain may have multiple TXT records associated with it, provided the DNS server implementation supports this. Each record can in turn have one or more character strings. Traditionally these text fields were used for a variety of non-standardised uses, such as a full company or organisation name, or the address of a host. In 1993 RFC 1464 proposed a simple approach to storing attributes and their values in these text fields. This is now used extensively in: * Verification of domain ownership * Implementation of Sender Policy Framework (SPF) * DomainKeys Identified Mail (DK ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Business Email Compromise Attacks
Email spoofing is the creation of email messages with a forged sender address. The term applies to email purporting to be from an address which is not actually the sender's; mail sent in reply to that address may bounce or be delivered to an unrelated party whose identity has been faked. Masked email is a different topic, providing a "masked" email address that is not the user's normal address, which is not disclosed (for example, so that it cannot be harvested), but forwards mail sent to it to the user's real address. The original transmission protocols used for email do not have built-in authentication methods: this deficiency allows spam and phishing emails to use spoofing in order to mislead the recipient. More recent countermeasures have made such spoofing from internet sources more difficult but not eliminated it; few internal networks have defenses against a spoof email from a colleague's compromised computer on that network. Individuals and businesses deceived by spoof e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Email Spoofing
Email spoofing is the creation of email messages with a forged sender address. The term applies to email purporting to be from an address which is not actually the sender's; mail sent in reply to that address may bounce or be delivered to an unrelated party whose identity has been faked. Masked email is a different topic, providing a "masked" email address that is not the user's normal address, which is not disclosed (for example, so that it cannot be harvested), but forwards mail sent to it to the user's real address. The original transmission protocols used for email do not have built-in authentication methods: this deficiency allows spam and phishing emails to use spoofing in order to mislead the recipient. More recent countermeasures have made such spoofing from internet sources more difficult but not eliminated it; few internal networks have defenses against a spoof email from a colleague's compromised computer on that network. Individuals and businesses deceived by spoof ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Murray Kucherawy
Murray S. Kucherawy is a computer scientist, mostly known for his work on email standardization and open source software. He originated in Canada where he studied Mathematics, specializing in Computer Science, Combinatorics and Optimization at the University of Waterloo, earning a Bachelor's degree in 1994. He worked for several Internet companies, including Sendmail, Cloudmark, and Facebook, which is his current employer (as of 2022). At the same time, he leaded several IETF The Internet Engineering Task Force (IETF) is a standards organization for the Internet and is responsible for the technical standards that make up the Internet protocol suite (TCP/IP). It has no formal membership roster or requirements and a ... working groups, including MARF, WEIRDS, and DMARC. He also wrote several RFCs (see below) and papers. In concert with such activity, he created various open source software packages, including OpenDKIM and OpenDMARC, in the framework of The Trusted Domain P ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phishing
Phishing is a type of social engineering where an attacker sends a fraudulent (e.g., spoofed, fake, or otherwise deceptive) message designed to trick a person into revealing sensitive information to the attacker or to deploy malicious software on the victim's infrastructure like ransomware. Phishing attacks have become increasingly sophisticated and often transparently mirror the site being targeted, allowing the attacker to observe everything while the victim is navigating the site, and transverse any additional security boundaries with the victim. As of 2020, phishing is by far the most common attack performed by cybercriminals, the FBI's Internet Crime Complaint Centre recording over twice as many incidents of phishing than any other type of computer crime. The first recorded use of the term "phishing" was in the cracking toolkit AOHell created by Koceilah Rekouche in 1995; however, it is possible that the term was used before this in a print edition of the hacker magazin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Abuse Reporting Format
The Abuse Reporting Format (ARF) also known as the Messaging Abuse Reporting Format (MARF) is a standard format for reporting spam via email. History A draft describing a standard format for feedback loop (FBL) reports was posted by Yakov Shafranovich in April 2005 and evolved to the current . AOL, who pioneered the field in 2003, initially used a different format, and converted to this ''de facto'' standard in 2008. Feedback loops don't ''have'' to use ARF, but most do. In January 2010, the IETF chartered a new working group working towards the goal of standardizing the ARF format. The WG was called Messaging Abuse Reporting Format WG or MARF, which produced . In 2012 it was extended by and to define ''Failure Reports'', for reporting email authentication failures. In 2015, the latter report type was further extended by to define DMARC's Failure Reports. Purpose The ARF format is designed to be extensible, providing for generic spam reporting, e.g. from users to some anti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Public Suffix List
The Public Suffix List (PSL) is a catalog of certain Internet domain names. Entries on the list are also referred to as effective top-level domains (eTLD). The Mozilla Foundation initiated the suffix list for the security and privacy policies of its Firefox web browser, but it is widely applied, with varying success, to a variety of other purposes under the Mozilla Public License (MPL). List The list is used by Mozilla browsers (Firefox), by Google in Chrome and Chromium projects on certain platforms, and by Opera. According to Mozilla, While ''com'', ''uk'', and ''us'' are top-level domains (TLDs), Internet users cannot always register the next level of domain, such as "co.uk" or "wy.us", because these may be controlled by domain registrars. By contrast, users can register second level domains within ''com'', such as ''example.com'', because registrars control only the top level. The Public Suffix List is intended to enumerate all domain suffixes controlled by registrars. An i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Email Forwarding
Email forwarding generically refers to the operation of re-sending an email message delivered to one email address to one or more different email addresses. The term ''forwarding'', used for mail since long before electronic communications, has no specific technical meaning,In section 3.9.2 ''List'' of RFC 5321, the term ''forwarding'' is used ambiguously. It notes that "''the key difference between handling aliases (Section 3.9.1) and forwarding (this subsection) is the change to the 'Return-Path'' header'." That wording, new w.r.t. RFC 2821, could be interpreted as the definition of ''forwarding'', if the same term weren't used at the beginning of the same subsection with the opposite meaning. As a contributor to RFC 5321 agreed, but it implies that the email has been moved "forward" to a new destination. Email forwarding can also redirect mail going to a certain address and send it to one or more other addresses. Vice versa, email items going to several different addresses can ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GNU Mailman
GNU () is an extensive collection of free software (383 packages as of January 2022), which can be used as an operating system or can be used in parts with other operating systems. The use of the completed GNU tools led to the family of operating systems popularly known as Linux. Most of GNU is licensed under the GNU Project's own General Public License (GPL). GNU is also the project within which the free software concept originated. Richard Stallman, the founder of the project, views GNU as a "technical means to a social end". Relatedly, Lawrence Lessig states in his introduction to the second edition of Stallman's book ''Free Software, Free Society'' that in it Stallman has written about "the social aspects of software and how Free Software can create community and social justice". Name ''GNU'' is a recursive acronym for "GNU's Not Unix!", chosen because GNU's design is Unix-like, but differs from Unix by being free software and containing no Unix code. Stallman chose th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
