Spam
Spam refers to an irrelevant or inappropriate message sent on the Internet to a large number of recipients. These messages are often used by scammers to trick people into providing their personal data so that they can be used to blackmail the person. Normally, spam offers an advertisement which is not validated under the actual name of organization.
Spear Phishing
Spear phishing describes when phishing is done with specific targets in mind; this allows messages to these people to appear more legitimate, or as if they are being sent by a legitimate user. For example, a person may get an offer from an organization that he knows. He might click on it and provide confidential information, perhaps to log-in to the website. In reality, the message is not from the actual organization, and he has given his credentials to the actual site to the spear-phisher.
Spider
A spider is a program that visits Web sites and reads their pages and other information in order to create entries for a search engine index. All major search engines on the Web have these kinds of programs, which are also known as "crawlers" or a "bots". Spiders are usually programmed to visit sites that have been marked by their owners as fresh or modernized.
Spoofs
A spoofing attack is when a malicious party impersonates another device or user on a network in order to launch attacks against network hosts, steal data, spread malware or bypass access controls.
Spyware
Spyware is software that can be installed on a computer system or computer device without the device user's knowledge. The software allows the installer to directly obtain or convert information from a computer and to transmit all that data to their own hard drive.