A Domain Name System blocklist, Domain Name System-based blackhole list, Domain Name System blacklist (DNSBL) or real-time blackhole list (RBL) is a service for operation of mail servers to perform a check via a Domain Name System (DNS) query whether a sending host's IP address is blacklisted for email spam. Most mail server software can be configured to check such lists, typically rejecting or flagging messages from such sites.
A web hosting service is a type of Internet hosting service that hosts websites for clients, i.e. it offers the facilities required for them to create and maintain a site and makes it accessible on the World Wide Web. Companies providing web hosting services are sometimes called web hosts.
Various anti-spam techniques are used to prevent email spam.
Email spam, also referred to as junk email, spam mail, or simply spam, is unsolicited messages sent in bulk by email (spamming). The name comes from a Monty Python sketch in which the name of the canned pork product Spam is ubiquitous, unavoidable, and repetitive. Email spam has steadily grown since the early 1990s, and by 2014 was estimated to account for around 90% of total email traffic.
A botnet is a group of Internet-connected devices, each of which runs one or more bots. Botnets can be used to perform Distributed Denial-of-Service (DDoS) attacks, steal data, send spam, and allow the attacker to access the device and its connection. The owner can control the botnet using command and control (C&C) software. The word "botnet" is a portmanteau of the words "robot" and "network". The term is usually used with a negative or malicious connotation.
The Spamhaus Project is an international organisation based in the Principality of Andorra, founded in 1998 by Steve Linford to track email spammers and spam-related activity. The name spamhaus, a pseudo-German expression, was coined by Linford to refer to an internet service provider, or other firm, which spams or knowingly provides service to spammers.
Email harvesting or scraping is the process of obtaining lists of email addresses using various methods. Typically these are then used for bulk email or spam.
Leonid Aleksandrovitch Kuvayev, who usually goes by the name of Leo, is a Russian/American spammer believed to be the ringleader of one of the world's biggest spam gangs. In 2005, he and six business partners were fined $37 million as a result of a lawsuit brought by the Massachusetts attorney general. It was found that they were responsible for millions of unsolicited e-mails per day. According to Spamhaus he could be the "Pharmamaster" spammer who performed a denial-of-service attack (DDoS) against the BlueSecurity company. Kuvayev is also behind countless phishing and money mule recruiting sites hosted on botnets. He has been called a "spam czar", and a "virtual criminal".
SpamCop is an email spam reporting service, allowing recipients of unsolicited bulk or commercial email to report IP addresses found by SpamCop's analysis to be senders of the spam to the abuse reporting addresses of those IP addresses. SpamCop uses these reports to compile a list of computers sending spam called the "SpamCop Blocking List" or "SpamCop Blacklist" (SCBL).
SORBS is a list of e-mail servers suspected of sending or relaying spam. It has been augmented with complementary lists that include various other classes of hosts, allowing for customized email rejection by its users.
Bulletproof hosting (BPH) is technical infrastructure service provided by an Internet hosting service that is resilient to complaints of illicit activities, which serves criminal actors as a basic building block for streamlining various cyberattacks. BPH providers allow online gambling, illegal pornography, botnet command and control servers, spam, copyrighted materials, hate speech and misinformation, despite takedown court orders and law enforcement subpoenas, allowing such material in their acceptable use policies.
CyberBunker is an Internet service provider located in the Netherlands and Germany that, according to its website, "hosted services to any website except child pornography and anything related to terrorism". The company first operated in a former NATO bunker in Zeeland, and later in another former NATO bunker in Traben-Trarbach, Germany.
On Internet usage, an email bomb is a form of net abuse that sends large volumes of email to an address to overflow the mailbox, overwhelm the server where the email address is hosted in a denial-of-service attack or as a smoke screen to distract the attention from important email messages indicating a security breach.
The Russian Business Network is a multi-faceted cybercrime organization, specializing in and in some cases monopolizing personal identity theft for resale. It is the originator of MPack and an alleged operator of the now defunct Storm botnet.
Backscatter is incorrectly automated bounce messages sent by mail servers, typically as a side effect of incoming spam.
In computing, a blacklist, disallowlist, blocklist, or denylist is a basic access control mechanism that allows through all elements, except those explicitly mentioned. Those items on the list are denied access. The opposite is a whitelist, allowlist, or passlist, in which only items on the list are let through whatever gate is being used. A greylist contains items that are temporarily blocked until an additional step is performed.
Since Internet users and system administrators have deployed a vast array of techniques to block, filter, or otherwise banish spam from users' mailboxes and almost all Internet service providers forbid the use of their services to send spam or to operate spam-support services, special techniques are employed to deliver spam emails. Both commercial firms and volunteers run subscriber services dedicated to blocking or filtering spam.
With email spam, which involves the unwanted inundation of unsolicited bulk emails, an array of user-side anti-spam techniques have been developed. These are methods created on the client arrangement of a situation, as opposed to the server-side.
Festi is a rootkit and a botnet also known by its alias of Spamnost, and is mostly involved in email spam and denial of service attacks. It works under operating systems of the Windows family. Autumn of 2009 was the first time Festi came into the view of the companies engaged in the development and sale of antivirus software. At this time it was estimated that the botnet itself consisted of roughly 25.000 infected machines, while having a spam volume capacity of roughly 2.5 billion spam emails a day. Festi showed the greatest activity in 2011-2012. More recent estimates - dated August 2012 - display that the botnet is sending spam from 250,000 unique IP addresses, a quarter of the total amount of one million detected IP's sending spam mails. The main functionality of botnet Festi is spam sending and implementation of cyberattacks like "distributed denial of service".
Proton Mail is a Swiss end-to-end encrypted email service founded in 2013 headquartered in Plan-les-Ouates, Switzerland. It uses client-side encryption to protect email content and user data before they are sent to Proton Mail servers, unlike other common email providers such as Gmail and Outlook.com. The service can be accessed through a webmail client, the Tor network, or dedicated iOS and Android apps.
