External Threats
Malware
Malware (short for malicious software) is any program written to damage a device, steal data or make a system carry out actions the owner never agreed to. It is an external threat because it arrives from outside the organisation, and it is usually created for money or to break into systems.
Types of malware
| Type | What it does |
|---|---|
| Virus | Attaches itself to a file or program and runs when that file is opened, copying itself into other files |
| Worm | Spreads by itself across a network, infecting device after device without anyone opening a file |
| Botnet | Links many infected computers into one network that the attacker controls remotely |
| Rootkit | Hides itself and other malware deep inside the operating system so it is very hard to detect |
| Trojan | Disguises itself as a genuine, useful program so you install it willingly |
| Ransomware | Encrypts your files or whole drive and demands payment to unlock them |
| Spyware | Secretly records what you do, such as keystrokes, passwords and the sites you visit |
Ransomware is one of the most damaging types. Imagine a small bakery whose till computer holds every order and supplier record: the files are scrambled, a message appears demanding payment for the decryption key, and trading stops until the data is restored. Paying does not guarantee you get the key back, which is why regular backups matter.
How malware hides and spreads
Malware rarely announces itself. A rootkit buries itself in the system files, and a Trojan looks like an innocent download, so an infected machine may keep working normally. Once inside, many types spread to other devices on the same network, so one careless download can affect a whole office.
Malware can reach a device by any route that lets files or data arrive: infected removable media, open or unencrypted Wi-Fi, downloads from an untrusted website, or a malicious email attachment or link. Just receiving a message is not enough, because the harmful program only runs once you open the attachment or click the link. Any device that runs software can be affected, including desktop computers, laptops, phones and smart TVs.
Practise this
Pearson BTEC Digital Information Technology · External Threats