| CipherTrust Glossary of Terms |
| Address harvester : |
A robot that scours the internet searching for valid email addresses in websites. See: Harvesting |
| Autoresponders : |
Programs that automatically generate emails based on an incoming email. Examples include systems that automatically acknowledge receipt of an email sent to a company. |
| Base64 : |
Base64 is a method of encoding binary data sent as an attachment through email. Base64 encoding divides three bytes of data into four bytes of ASCII text, making the resulting file size approximately 33% larger. |
| Bayesian filtering : |
A method of rating a message based on several factors to determine whether the mail is spam. Over time, the Bayesian method learns from messages that are marked as spam by the user, and builds its rules accordingly. |
| Bayesian logic : |
Named for Thomas Bayes, an English mathematician, Bayesian Logic is a branch of logic applied to decision making and inferential statistics that deals with probability inference. Some spam filters use Bayesian Logic to determine the probability that a given email message is spam by comparing the contents of the email to the contents of known spam. Individual keywords are rated for their statistical likelihood of being spam words, when the individual scores are totalled up, a probability is calculated for the entire email being spam. |
| BCC : |
BCC is a method of hiding certain recipients of an email from the rest of the recipients. |
| Blacklist : |
As regarding spam, blacklists are lists of known spammers, their IP addresses, and/or their ISP (Internet Service Provider). Using this information, spam filters can block all messages coming from known spammers and/or their ISPs. ISPs that fail to discipline spammers may find all email from their legitimate customers blocked by large numbers of recipients. This tactic forces the ISP to take action against spammers using their systems because legitimate users do not want to be inconvenienced by having their email blocked. The opposite of a whitelist. |
| Body : |
As it regards to email, the body is the main part of the email that contains the text and images the user types in. In addition to the body, emails also contain headers which are used to route the email. |
| Bounced Message : |
An email that is returned to the sender because the email was not deliverable (usually because the email address does not exist). |
| Click-Through Rate : |
Measures the percentage of people who click on a link in an email. |
| Complex dictionary checking : |
A word canning technique that is designed to detect word replacements such as "h0me m0rtgages". |
| Dictionary attack : |
Similar to a password cracking program, this type of spam attack methodically sends emails in an alphabetic order to a mail server, in the hopes of getting some correct. |
| Direct Delivery : |
The ability of an email program to deliver email directly to each recipient without using an intermediate mail server. This method defeats efforts to have ISP’s block spammers since the spammers can circumvent the ISP's involvement in the mail process. Direct Delivery, however, is much slower for the spammer because his computer must make each connection individually instead of just once to the ISP's email server. This increases the load on the spammer's computer, while eliminating it for his ISP. |
| Domain Name System Block Lists (DNSBL) : |
A list of domains that does not try to prevent spammers from sneding mail through their servers. |
| Double Opt-In : |
Technically, this is when a user has elected to receive an email from a marketer, and then confirmed his/her decision usually by responding to an email confirmation. In practice, however, some less conscientious marketers have looser definitions of double opt-in which can include those who have received more than one email from a spammer but did not explicitely ask to be removed from the spammer's list. |
| Email Client : |
A program used by the user to read and send email messages. As opposed to the email server, which is used to transport email from one location to another. |
| Email Server : |
A program running on a server that is constantly connected to the internet. The email server is the point of contact for the email client, and is responsible for transporting the email from the sender to the recipient's email server. Email servers also store email data prior to delivery. |
| Encoding : |
The process of formatting non-text data into ASCII format so that it can be sent as an attachment with an email. Email can only handle 7-bit ASCII text, however many types of files such as images are not saved as text; they are binary files. In order to send non-text binary information, the data must first be encoded into ASCII format on the sender's side, and decoded using the same procedure on the receiver's side. Common encoding methods include: MIME, BinHex, Uuencode, and Base64. |
| False negative : |
An email that is marked as legitimate, even though it is spam. |
| False positive : |
An email that is marked as spam, even though it is legitimate. |
| Flame : |
Any angry or rude message sent electronically through email, listservs, instant messaging, or public discussion forums. |
| Greylist : |
The midpoint between a whitelist and a blacklist. Senders not on the blacklist or the whitelist may be placed on a greylist. |
| Hacker : |
Someone who intentionally tries to access information or systems to which they are not intended to have access. |
| Harvesting : |
The process of scouring the internet to find valid email addresses. See: Address Harvester |
| Header : |
The part of an email message that is usually not displayed in the email client. The email header contains meta-data and routing information such as the identity and IP addresses of the sender and recipient as well as all email gateways in between the sender and the recipient and the email's priority and subject line. Some spammers deliberately manipulate the header information in an attempt to fool (or spoof) spam filters as to the actual source of the email message. |
| Identity Theft : |
Stealing a victim's personal information. Often, identity thieves will open credit accounts in the victim's name. Identity theft is a danger of falling victim to a phishing attempt. |
| IMAP : |
(Internet Message Access Protocol) - IMAP is the method used to access email remotely, usually through the use of webmail or other protocol that does not download the messages to the client machine. It allows for messages to be kept in multiple folders, supports folder sharing, and online mail handling. IMAP is a more advanced method of storing mail than POP which relies on downloading messages to a user's local drive. |
| J : |
There are no definitions for this letter. |
| K : |
There are no definitions for this letter. |
| LDAP : |
(Lightweight Directory Access Protocol) - A method used to access directory information, and is used by email clients to look up email addresses. |
| Listwashing : |
Removing email addresses from a mailing list, after receiving opt-out requests. |
| Mail Bomb : |
The act of sending large numbers of large email messages to the same server or email address in an attempt to cause heavy loads which result in performance loss or server failure. |
| Mailer Daemon : |
Unix program used to manage email. |
| Mailing List : |
List of email addresses. |
| MIME : |
(Multipurpose Internet Mail Extensions) - MIME is a method of encoding binary data into ASCII strings for the purpose of transferring files via email. |
| Morph : |
Changing an email's header to avoid detection by spam filters. |
| Munging : |
An attempt to hide an email address from harvesters. For example, posting your email address as "user at domain dot com" instead of as "user@domain.com" |
| NDR spam : |
False undelieverable email that attempts to trick the victim into opening the attachment, attempting to take advantage of the fact that Microsoft Exchange servers send undeliverable emails back as attachments. |
| Network check (a.k.a. RDC Check ) : |
Checking a sender's IP address against a known list of spammers and legitimate senders to assist in determining whether or not a message is spam. |
| Obfuscation : |
See Munging |
| Open relay : |
Most modern email servers will not allow unauthorized users to send email through them. Some email servers, however, will allow outsiders to send (or relay) email through them. These servers are known as "Open Relay Servers". |
| OpenPGP : |
An encryption standard for email that allows sender authentication using digital signatures and can be encrypted using public key cryptography to protect privacy. OpenPGP builds on and extends MIME. OpenPGP messages inter-operate well with any standard-compliant email client |
| Opt-in : |
Technically, opt-in email marketing means sending marketing messages only to people who explicitly requested them. If a customer asks for a specific piece of information, you have the permission to send that information and nothing more. In practice, however, some spammers consider anyone who hasn't explicitely "opted-out" to be "opt-in". |
| Opt-out : |
The practice of explicitely asking not to be contacted via email. |
| Phishing : |
The act of tricking the victim into giving out personal information. For example, sending out an email that looks like it came from ebay that directs a user to log in and provide credit card information. The sender is not, however, legitimate, and will capture this information. |
| POP/POP3 : |
(Post Office Protocol) - A mail protocol that leaves the user's email on the server until he or she connects to the server and downloads it to the local machine. Whereas SMTP describes the way email is transferred from server to server, POP describes the method in which the email client communicates with the email server. |
| Public Key Cryptography : |
This form of encryption uses two parts. The public key is used for encryption exclusively for the recipient while the private key is known only to the recipient and is used for decryption. This technology is used in OpenPGP email messages to encrypt email. |
| Q : |
There are no definitions for this letter. |
| Ratware : |
Mass mailing software used by spammers. |
| Reverse DNS Check (RDC) : |
See Network Check |
| S/MIME : |
(Secure Multipurpose Internet Mail Extensions) - Also known as SMIME or S-MIME, A standard for secure email messages, S/MIME allows for sender authentication using digital signatures, and can be encrypted.
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| SMTP : |
Simple Mail Transfer Protocol. The most common protocol used for transferring e-mail across the Internet.
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| Social engineering : |
The act of conning someone into giving out personal information. |
| Spam : |
Unsolicited bulk email generally sent for commercial or political purposes, and always sent using an automated email program. |
| Spammer : |
A person who sends spam |
| Spam trap : |
An unused email address that is used online to gather any spam messages. For example, signing up for a newsletter or internet forum with a spam trap will keep a user's "real" email address hidden. |
| Spoofing : |
Altering an email's sending address so as to appear to be from a different sender. |
| Subject : |
As it pertains to email, the subject is a piece of meta-data recorded by the message sender and stored in the email's header. The subject is usually displayed in the email client and is one of the only pieces of information in the email header that is generally viewed by the email's recipient. |
| Tarpitting : |
Monitoring mail traffic to identify mass mailers, or senders who are sending an unusually large number of messages. |
| U : |
There are no definitions for this letter. |
| V : |
There are no definitions for this letter. |
| Webmail : |
Also called Web-based Email, Webmail is an email account that is accessed through a Web browser. Popular consumer versions of this technology include HotMail and Yahoo Mail. Many corporations are also adopting Webmail as a way to allow employees to access their email accounts remotely.
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| Web bug : |
A small or invisible image placed in an email that lets spammers know that the message was received and seen. |
| Whitelist : |
A list of entities that are allowed from sending messages through. The opposite of a blacklist. A whitelist will allow all entities on the list to send messages, and disallow messages from any other entitiy. |
| Worm : |
A worm is a type of computer virus that replicates itself and moves through a network, typically travelling by sending new copies of itself via email. Examples of worms are Nimda, MyDoom, and Netsky. |
| X : |
There are no definitions for this letter. |
| Y : |
There are no definitions for this letter. |
| Zombie : |
A computer that has been hijacked, and is being used to send out spam or other malicious attacks. |
