Common threats (malware, phishing, ransomware) in Intro to Computing - Practice Problems & Coding Challenges

Challenge - 5 Problems

🧠 Conceptual

intermediate

Identify the type of threat from a scenario

You receive an email that looks like it is from your bank asking you to click a link and enter your password to verify your account. What type of threat is this?

A Spyware

B Ransomware

C Malware

D Phishing

💡 Hint

Think about what the attacker wants: your personal information by tricking you.

This is a classic example of phishing, where attackers try to trick you into giving sensitive information by pretending to be a trusted source.

🧠 Conceptual

intermediate

Understanding ransomware behavior

A computer suddenly shows a message demanding payment to unlock files. What has most likely happened?

A The computer is running a software update

B The computer has a virus that deletes files

C The computer is infected with ransomware

D The computer is infected with spyware

💡 Hint

Think about what ransomware does to your files and what it demands.

Ransomware encrypts files and demands payment to restore access. The message demanding payment is a key sign.

❓ trace

advanced

Trace the infection path of malware

A user downloads a free game from an unknown website. Soon after, their computer slows down and shows many pop-up ads. What type of malware is most likely causing this?

A Adware

B Ransomware

C Trojan horse

D Worm

💡 Hint

Think about malware that causes unwanted ads and slows down the computer.

Adware displays unwanted advertisements and can slow down the system. It often comes bundled with free software.

❓ identification

advanced

Identify the threat from a description of its effect

Which threat type secretly records your keystrokes to steal passwords and credit card numbers?

A Spyware

B Ransomware

C Virus

D Phishing

💡 Hint

This threat spies on your activity without your knowledge.

Spyware secretly monitors user activity like keystrokes to steal sensitive information.

❓ Comparison

expert

Compare malware types by their main goal

Match each threat to its primary goal:

1. Ransomware
2. Phishing
3. Worm
4. Trojan horse

Options:
A. Spread copies of itself to other computers
B. Trick users into revealing sensitive information
C. Lock files and demand payment
D. Disguise as legitimate software to cause harm

A 1:D, 2:C, 3:B, 4:A

B 1:C, 2:B, 3:A, 4:D

C 1:B, 2:A, 3:D, 4:C

D 1:A, 2:D, 3:C, 4:B

💡 Hint

Think about what each threat tries to do: spread, trick, lock, or disguise.

Ransomware locks files and demands payment (C). Phishing tricks users to reveal info (B). Worms spread copies (A). Trojan horses disguise as legit software (D).

Practice

1. Which of the following best describes phishing?

easy

A. Tricking someone to reveal personal information

B. Locking files and demanding money

C. Damaging or deleting files on a device

D. Improving device performance

Solution

1. Step 1: Understand phishing concept

   Phishing is a trick to get personal info by pretending to be trustworthy.

2. Step 2: Compare options to phishing

   Only Tricking someone to reveal personal information matches this description exactly.

3. Final Answer:

   Tricking someone to reveal personal information -> Option A

4. Quick Check:

   Phishing = Tricking for info [OK]

Hint: Phishing tricks you to share info, not damage files [OK]

Common Mistakes:

• Confusing phishing with ransomware
• Thinking phishing damages files
• Mixing phishing with malware

2. Which of these is the correct description of ransomware?

easy

A. Software that deletes your files permanently

B. Software that locks your files and asks for money

C. A scam email asking for your password

D. A program that speeds up your computer

Solution

1. Step 1: Recall ransomware behavior

   Ransomware locks files and demands payment to unlock them.

2. Step 2: Match options to ransomware

   Software that locks your files and asks for money exactly matches this behavior.

3. Final Answer:

   Software that locks your files and asks for money -> Option B

4. Quick Check:

   Ransomware = Locks files + money demand [OK]

Hint: Ransomware locks files and demands money, not deletes permanently [OK]

Common Mistakes:

• Confusing ransomware with malware that deletes files
• Thinking ransomware is a phishing scam
• Believing ransomware improves performance

3. Look at this scenario:

"You receive an email asking to click a link to verify your bank details. The link leads to a fake website."

What type of threat is this?

medium

A. Phishing

B. Ransomware

C. Malware

D. Spyware

Solution

1. Step 1: Analyze the scenario

   The email tries to trick you into giving bank details via a fake website.

2. Step 2: Identify the threat type

   This is classic phishing: tricking for personal info using fake sites.

3. Final Answer:

   Phishing -> Option A

4. Quick Check:

   Fake site + trick = Phishing [OK]

Hint: Fake websites asking for info usually mean phishing [OK]

Common Mistakes:

• Confusing phishing with ransomware
• Thinking malware always damages files
• Assuming spyware is the same as phishing

4. A user reports their files are locked and a message demands payment. Which step fixes the problem?

medium

A. Click the payment link to unlock files

B. Ignore the message and continue working

C. Run antivirus software and disconnect from the internet

D. Share your password with the sender

Solution

1. Step 1: Identify the threat

   Locked files and payment demand indicate ransomware infection.

2. Step 2: Choose safe recovery action

   Running antivirus and disconnecting stops spread and helps remove ransomware safely.

3. Final Answer:

   Run antivirus software and disconnect from the internet -> Option C

4. Quick Check:

   Ransomware fix = Antivirus + disconnect [OK]

Hint: Never pay ransom; use antivirus and isolate device [OK]

Common Mistakes:

• Paying ransom immediately
• Ignoring the problem
• Sharing passwords with attackers

5. A company wants to protect employees from malware, phishing, and ransomware. Which combined approach is best?

hard

A. Disable all internet access permanently

B. Only install antivirus software and ignore employee training

C. Ask employees to share passwords to detect phishing

D. Install antivirus, train employees on suspicious emails, and backup data regularly

Solution

1. Step 1: Understand threats and protections

   Malware needs antivirus, phishing needs training, ransomware needs backups.

2. Step 2: Evaluate options

   Install antivirus, train employees on suspicious emails, and backup data regularly combines antivirus, training, and backups, covering all threats effectively.

3. Final Answer:

   Install antivirus, train employees on suspicious emails, and backup data regularly -> Option D

4. Quick Check:

   Combined defense = Antivirus + Training + Backup [OK]

Hint: Best defense combines software, training, and backups [OK]

Common Mistakes:

• Relying only on antivirus
• Ignoring employee awareness
• Disabling internet is impractical