Internet and network attacks and security threats
Security threats include malware, phishing, denial-of-service attacks, unauthorised access, and hardware or data theft, all of which can harm a business.
Types of malware (malicious software)
| Type | How it works |
|---|---|
| Virus | Attaches itself to a file or program and spreads when that file is opened |
| Worm | Copies itself across networks on its own, without a host file |
| Trojan horse | Looks like useful software but hides harmful code |
| Ransomware | Locks (encrypts) files and demands payment to unlock them |
| Spyware and keyloggers | Secretly record activity, such as passwords typed |
| Adware | Shows unwanted advertisements |
Internet and network attacks
| Attack | What happens |
|---|---|
| Phishing | Fake emails or websites trick users into giving passwords, OTPs or card details |
| Denial of service (DoS) | A server is flooded with traffic so real customers cannot reach it |
| Distributed DoS (DDoS) | The flood comes from many hijacked computers (a botnet) at once |
| Unauthorised access (hacking) | Someone enters a system without permission |
| Spoofing | Faking an email address, website or IP address to look trusted |
| Man-in-the-middle | Secretly intercepting data in transit, e.g. on open public Wi-Fi |
| Back door | A hidden way of getting past normal security checks |
How a phishing attack works
The attack succeeds only if a person is fooled, so training staff and customers is the main defence.
Other security risks
- Hardware theft and vandalism: stolen laptops and phones.
- Software theft: piracy and illegal copying.
- Information theft: stealing customer or card data.
- System failure: power cuts, voltage surges, hardware faults.
- Natural disasters: floods and fire.
- Insider threats: careless or dishonest staff.
Sri Lankan banks and Sri Lanka CERT warn customers never to share OTPs or passwords by SMS or phone, because smishing and vishing scams that pretend to be banks, couriers or prize offers are a real risk for both customers and businesses.
Short answer: “What is ransomware?” Malware that encrypts a victim's files and demands payment to unlock them.
Structured question: “Distinguish between a virus, a worm and a trojan horse.” A virus needs a host file and spreads when it is opened; a worm spreads by itself across networks; a trojan pretends to be useful software.
Essay: “Discuss the types of internet and network attacks and security threats faced by a business.” Explain malware types, phishing and social engineering, DoS/DDoS, hacking, spoofing and interception, then physical and other risks, with their effects.
Malware family: 'Very Worried Traders Rarely Sleep' = Virus, Worm, Trojan, Ransomware, Spyware.