02.06.2016 |

Episode #4 of the course Cyber security basics by FutureLearn


Malware is malicious software designed to disrupt or damage data, hardware, or software and can access your computer in a variety of ways, typically by exploiting a combination of human and technical factors. Malware might be contained in a link or attachment you receive in an email, for example. Or it could be in illegal software or a film you download from the internet. There are several types of malware, such as viruses, trojans, spyware, and worms. Here’s how they commonly work.


A virus is a small software program written to copy itself into applications, data, and a computer’s hard disk. Capable of corrupting or deleting data or even erasing everything on the hard disk, viruses are typically transmitted on devices such as flash memory cards or through the internet, such as in pirated software downloads or in email message attachments and instant messaging (IM). In emails and IM, viruses can be disguised as attachments of images, greeting cards, or audio or video files.


Worms spread through network connections, accessing uninfected machines and then hijacking their resources to transmit copies of themselves across the network. Most worms begin as email attachments that infect a computer when they’re opened. They frequently mimic the “From” addresses in email messages, making it appear that an infected message is from someone you know. They then spread automatically through email messages, networks, or operating system vulnerabilities. While worms aren’t always destructive to computers, even the most benign worm will consume resources and cause computer and network performance issues.


Named after the wooden horse that smuggled Greek soldiers into the ancient city of Troy, a trojan or trojan horse is a malicious software program that hides inside “legitimate” programs (such as screensavers), causing damage behind the scenes. Trojans do not usually spread by themselves but are spread by viruses, worms, or downloaded software. They can allow someone else to gain control of the computer, and the invader can then copy or delete personal information, monitor keystrokes, or use email software to pass the trojan onto other computers.


Spyware are programs that secretly record what you do on your computer. Not all spyware is malicious, but at its worst, it can track and capture your personal information such as passwords and banking information. Spyware tends to work quietly in the background, so you might not know it is there. Often, it deceives users by bundling itself in with desirable software you download online, such as shareware or freeware. Unlike viruses and worms, systems infected with spyware typically don’t attempt to transmit or copy the software to other computers.


Recommended free course

Introduction to Cyber Security


Recommended book

“Cybersecurity 101: What You Absolutely Must Know! – Volume 1: Learn how not to be Pwned, Thwart Spear Phishing and Zero Day exploits, Cloud security basics and much more” by James Scott


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