Glossary

DKIM

DomainKeys Identified Mail (DKIM) permits a person, role, or organization that owns the signing domain “to claim some responsibility for a message by associating the domain with the message”. See RFC 6376

DMARC

Domain-based Message Authentication, Reporting, and Conformance is a “mechanism by which a mail-originating organization can express domain-level policies and preferences for message validation, disposition, and reporting, that a mail-receiving organization can use to improve mail handling”. See RFC 7489

DNS

The Domain Name System of the internet is the system used to link domain names to specific computers. If your browser wants to know at which IP address https://example.com lives it asks for a different record (‘A’ and ‘AAAA’ for IPv4 and IPv6 addresses respectively) than an email server would if it wanted to deliver an email for you@example.com (email needs the so called MX record, short for ‘Mail Exchange’). DNS records can be digitally signed, so you can check if they have been tampered with or not.

DNS record

An individual data element in the DNS system. DKIM, SPF and DMARC are all DNS records.

Phishing

Phishing is a particular type of untargeted online fraud where users are lured (often via bulk emails from domains not protected by modern email authenticity standards) by someone assuming a false identity. This often provides enough of a social engineering context to convince at least a percentages the recipients to provide sensitive information like login or credit card credentials, make a payment, etc.

Spearphishing

Spearphishing is the targeted version of phishing: some is actively targeting a specific organisation or individual, and is engaging in a personalised attack using OSINT information about that organisation (including names of colleagues, knowledge about products, etc). A well-known version of spearphishing is CEO fraud.

Spam

Email that is being sent in large amounts without any explicit requests for it being made by the recipients, for marketing or other purposes. Often senders exploit the computer and network resources of otherwise-uninvolved third parties. Also known as “Unsolicited Bulk Email”.

The IETF has defined Spam in RFC 2635 as follows:

The term “spam” as it is used to denote mass unsolicited mailings or netnews postings is derived from a Monty Python sketch set in a movie/tv studio cafeteria. During that sketch, the word “spam” takes over each item offered on the menu until the entire dialogue consists of nothing but “spam spam spam spam spam spam and spam.” This so closely resembles what happens when mass unsolicited mail and posts take over mailing lists and netnews groups that the term has been pushed into common usage in the Internet community.

SPF

Sender Policy Framework is an internet standard used to whitelist a list of IP addresses as legitimate senders of email. See RFC 7208

Parked domain

A parked domain is a domain name you have registered, but are not activly using. Commons scenario’s include registering for some future use, but many people also register domain names with alternative spellings (e.g. to thwart typosquatters) or otherwise make sure nobody else abuses a domain name similar to yours.