Computer Science/IT MCQs
Topic Notes: Computer Science/IT
MCQs and preparation resources for competitive exams, covering important concepts, past papers, and detailed explanations.
Plato
- Biography: Ancient Greek philosopher (427–347 BCE), student of Socrates and teacher of Aristotle, founder of the Academy in Athens.
- Important Ideas:
- Theory of Forms
- Philosopher-King
- Ideal State
11
What is the most widely spread computer worm?
Answer:
ILOVEYOU worm
The "ILOVEYOU" worm, which spread globally in 2000, is considered one of the most widespread and damaging computer viruses in history. It propagated via email as an attachment, causing billions of dollars in damages by overwriting files and sending itself to the victim's contacts.
12
What is a limitation of signature-based antivirus detection?
Answer:
It is ineffective against new, "zero-day" malware for which a signature has not yet been created.
The main weakness of signature-based detection is that it is purely reactive. It can only identify threats that are already known and have a signature in its database. It offers no protection against brand-new malware.
13
What is the primary infection vector for macro viruses?
Answer:
Malicious Microsoft Office documents (e.g., Word, Excel).
Macro viruses are written in a macro language and are embedded within documents. They spread when a user opens an infected document and enables macros, which allows the malicious code to run.
14
Which type of viruses are triggered by time or date?
Answer:
Time bombs
A time bomb is a piece of malware that is designed to execute its malicious payload at a specific date or time.
15
Why is it risky to download software from untrusted websites or peer-to-peer (P2P) file-sharing networks?
Answer:
The software is often bundled with hidden malware, such as Trojans or spyware.
Unofficial software download sources are a breeding ground for malware. Attackers often package Trojans or other malicious code with pirated or "free" versions of popular software.
16
What is "pharming"?
Answer:
A type of phishing attack that redirects a user to a fraudulent website, even if they type the correct URL.
Pharming is a sophisticated infection method where an attacker compromises DNS settings on a user's computer or a network's DNS server. This allows them to redirect traffic from a legitimate website to a fake, malicious one without the user's knowledge.
17
The Code Red worm (2001) exploited a vulnerability in what software?
Answer:
Microsoft's Internet Information Services (IIS) web server
Code Red spread by exploiting a buffer overflow vulnerability in Microsoft's IIS web server software. Once infected, a server would deface its own website and then begin scanning for other vulnerable servers to infect.
18
Malware that attaches itself to an executable file and requires a host program to spread is called a:
Answer:
Virus
A computer virus is a type of malicious code or program written to alter the way a computer operates and is designed to spread from one computer to another. It operates by inserting or attaching itself to a legitimate program or document that supports macros.
19
Which of the following can be a way for a computer virus to enter a system?
Answer:
Borrowed software copies
Using unauthorized or pirated software is a common way for computer viruses to be introduced to a system.
20
What is the most frequent virus entry point on a hard disk?
Answer:
Incoming Email
Email attachments are common carriers of viruses that can infect computers.