When customers of a Web site are unable to access it due to flooding of fake network traffic, it is known as
- (a)virus
- (b)Trojan horse
- (c)cracking
- (d)denial of service attack
Correct — D, denial of service (DoS) attack. Here the target's server or network is deliberately swamped with a huge volume of fake or junk requests, exhausting its bandwidth, memory or processing power so that genuine users can no longer reach the website. When the flood is launched from many hijacked machines at once, it becomes a Distributed Denial of Service (DDoS) attack.
- (a)virus — A virus is malicious code that attaches to a file or program and spreads when that file is run; it corrupts or replicates on a host machine — it is not the act of flooding a website with traffic to block access.
- (b)Trojan horse — A Trojan is malware disguised as legitimate software that tricks a user into installing it (often opening a backdoor); it deceives a user rather than overwhelming a site with traffic.
- (c)cracking — Cracking is breaking into a system or defeating its security/passwords for unauthorised access; the described attack denies service by overloading the site, not by breaking in.
A denial-of-service attack targets availability — one leg of the CIA triad (Confidentiality, Integrity, Availability) of information security. Instead of stealing or altering data, the attacker makes a service unusable by drowning it in bogus requests. The distributed version (DDoS) uses a 'botnet' of many compromised computers to amplify the flood.
The clue words are 'flooding' and 'unable to access' — it is availability that is under attack, not the confidentiality of data. Virus and Trojan describe how malware infects a machine; cracking is unauthorised entry. Only DoS matches 'flood the site with traffic so users can't get in.'
- A DoS attack overwhelms a server or network with fake traffic so legitimate users are denied access.
- A DDoS (Distributed DoS) launches the flood from many compromised machines (a botnet) simultaneously.
- It attacks 'availability' in the CIA triad — not confidentiality or integrity.
- It is distinct from a virus (self-replicating code), a Trojan (disguised malware) and cracking (unauthorised break-in).
- Attacker controls a botnet of hijacked computers
- Botnet sends a flood of fake requests to the target site
- Server's bandwidth / memory / processing is exhausted
- Genuine customers can no longer access the website
Availability is the target — the site is swamped with junk traffic, not broken into.
- Confusing a Trojan (disguised malware) with a DoS (traffic flood)
- Assuming any cyber-attack that blocks a site is generic 'hacking/cracking'
MPPSC repeatedly gives a one-line description of a cyber-threat and asks you to name it (phishing, Trojan, spoofing, DoS); UPSC frames cyber-security around the IT Act and data protection.
Which of the following is a type of cyber-attack that involves tricking users into revealing sensitive information?
- (a) Phishing attack
- (b) SQL Injection attack
- (c) DOS attack
- (d) None of the above
Answer(a) Phishing attack
Same skill — matching a described cyber-attack to its correct name; a 'DOS attack' even appears here as an option.
A malware, that looks like a legitimate software and once it tricks a user into installing it, acts pretty much like a virus or worm, is known as :
- (a) Keylogger
- (b) Ransomware
- (c) Trojan
- (d) Spyware
Answer(c) Trojan
Same skill — naming a cyber-threat from its behaviour; the 'Trojan' answer is exactly the distractor (b) in this question.
- practice — not a real PYQ
A DoS/DDoS attack primarily compromises which goal of information security?
- (a)Confidentiality
- (b)Integrity
- (c)Availability
- (d)Non-repudiation
Answer(c) Availability — the service is made unusable by overload.
- practice — not a real PYQ
A network of malware-infected computers controlled remotely to launch attacks such as DDoS is called a:
- (a)firewall
- (b)botnet
- (c)honeypot
- (d)VPN
Answer(b) botnet — the army of hijacked machines behind a DDoS flood.