Understanding Malware: Types, Symptoms, and How to Prepare for CompTIA A+
In today’s digital world, malware is more than just a buzzword—it's a serious threat to individuals, businesses, and entire networks. Whether you're studying for the CompTIA A+ certification or simply looking to protect your own systems, knowing the different types of malware and how they behave is essential. From ransomware that locks down your data to stealthy rootkits that hide in the shadows, each type of malware has its own method of attack—and symptoms that help you spot them.
In this post, we'll break down the major types of malware,
highlight common warning signs of infection, and help you test your knowledge
with a set of CompTIA A+–style quiz questions.
Comparative Table of Malware Types
|
Type of Malware |
Replication |
Activation |
Primary Function |
Persistence |
Delivery Method |
Example |
|
Virus |
Copies itself to other files or
disks |
Triggered by user or infected file |
Corrupt files, erase data, display
messages |
Low to moderate |
Infected files, removable media |
Early viruses on floppy disks |
|
Worm |
Replicates automatically over
networks |
Auto-executes upon arrival |
Spread rapidly, consume bandwidth |
Moderate |
Email, networks, exploits |
Email worms |
|
Trojan |
Does not replicate itself |
Installed by unsuspecting user |
Performs hidden malicious tasks |
Moderate |
Fake software, bundled downloads |
Fake games or cracked software |
|
Rootkit |
Does not replicate itself |
Activates at system boot |
Hides other malware, avoids
detection |
High |
Dropped by other malware or
exploits |
Early boot sector rootkits |
|
Ransomware |
Varies (often via phishing or
exploits) |
Encrypts files or locks system on
execution |
Demands ransom for access
restoration |
Moderate |
Phishing emails, exploit kits |
WannaCry, CryptoLocker |
|
Keylogger |
Does not replicate |
Runs silently in background |
Records keystrokes to steal info |
Low to moderate |
Trojan downloads, attachments |
Hidden keylogging software |
|
Spyware |
May replicate or piggyback |
Runs silently in background |
Tracks user activity and collects
data |
Low to moderate |
Bundled software, adware, email |
Adware tracking browsing habits |
Common Symptoms of Malware
|
Symptom |
Description |
|
Pop-ups |
Unexpected ads or messages appear
during browsing, even on trusted websites. |
|
Browser Redirection |
Your browser sends you to
unintended or suspicious websites. |
|
Security Alerts |
Frequent or unusual warnings from
antivirus or system security tools. |
|
Problems with Updates |
Difficulty installing updates for
your OS or apps, or updates fail entirely. |
|
Spam |
You receive or send odd spam emails
without your knowledge. |
|
Automated Replies |
You get email replies to messages
you didn’t send, indicating account misuse. |
|
Invalid Certificates |
Warnings about invalid or untrusted
website certificates while browsing. |
CompTIA
A+ Practice Quiz on Malware
Types and Symptoms
✅ Malware Types (15 Questions)
1.
Which type of malware disguises itself as legitimate software but
performs malicious actions?
A. Worm
B. Trojan
C. Keylogger
D. Rootkit
2.
Which malware type spreads automatically across a network without user
intervention?
A. Virus
B. Trojan
C. Worm
D. Spyware
3.
What is the main goal of ransomware?
A. To display ads
B. To encrypt files and demand payment
C. To monitor user activity
D. To infect other files
4.
Which malware type hides its presence and the presence of other malware
from the operating system?
A. Keylogger
B. Rootkit
C. Virus
D. Worm
5.
Which of the following does NOT replicate on its own?
A. Virus
B. Worm
C. Trojan
D. Rootkit
6.
Which malware is designed to log every key the user types?
A. Keylogger
B. Worm
C. Trojan
D. Rootkit
7.
Spyware is typically used to:
A. Spread malware over networks
B. Encrypt user files
C. Monitor and collect user activity
D. Replicate in boot sectors
8.
A virus requires what to replicate?
A. A network connection
B. User intervention
C. A rootkit
D. Admin privileges
9.
Which of the following can install during system boot and hide its
existence?
A. Spyware
B. Trojan
C. Rootkit
D. Keylogger
10.
Which malware is commonly spread through phishing emails and locks files?
A. Worm
B. Ransomware
C. Virus
D. Spyware
11.
Adware often comes bundled with:
A. Rootkits
B. Worms
C. Spyware
D. Viruses
12.
What is the primary distribution method for a keylogger?
A. Email virus
B. Infected document
C. Trojan
D. System update
13.
Which malware could create multiple copies of itself and crash a network?
A. Worm
B. Trojan
C. Virus
D. Spyware
14.
Which of the following is most likely to use system exploits to hide
itself?
A. Spyware
B. Keylogger
C. Rootkit
D. Ransomware
15.
A fake antivirus program demanding money is an example of:
A. Adware
B. Spyware
C. Ransomware
D. Keylogger
⚠️ Symptoms of Malware (15 Questions)
16.
You notice constant pop-ups when browsing the internet. This may
indicate:
A. Hardware failure
B. RAM issues
C. Malware infection
D. Slow internet
17.
If your browser is redirecting to strange websites, you likely have:
A. Rootkit
B. Pop-up blocker
C. Malware infection
D. VPN misconfiguration
18.
Receiving automated email replies to messages you didn't send may
suggest:
A. Keylogger
B. Rootkit
C. Email account compromise
D. Spam filter issue
19.
Which of the following symptoms indicates a potential malware infection?
A. Faster boot time
B. Invalid security certificates
C. System overheating
D. No audio
20.
Frequent fake security alerts are a sign of:
A. Ransomware
B. Rootkit
C. Rogue antivirus
D. Driver issue
21.
You cannot update your antivirus software. What might this indicate?
A. BIOS corruption
B. Malware blocking updates
C. Broken network card
D. Outdated license
22.
Which of the following is a common symptom of a spyware infection?
A. Loud fan noises
B. Unusual network activity
C. Frequent reboots
D. Inaccessible BIOS
23.
Which symptom is commonly caused by browser hijackers?
A. Invalid boot device
B. Redirected search results
C. Disabled firewall
D. Blank screen
24.
Spam emails being sent from your address without your knowledge suggests:
A. DNS misconfiguration
B. Account compromise
C. Expired SSL
D. Registry error
25.
Unexpected toolbars or plugins in your browser may be caused by:
A. Software patch
B. Spyware or adware
C. RAM error
D. File fragmentation
26.
Unusual system crashes and blue screens can be signs of:
A. Malware or driver conflicts
B. High CPU temperature
C. Insufficient RAM
D. Defragmentation
27.
Frequent redirects and pop-ups may indicate what kind of malware?
A. Adware
B. Worm
C. Virus
D. Rootkit
28.
Slow internet performance, combined with unknown processes, may point to:
A. Insufficient bandwidth
B. Malware activity
C. Power saving mode
D. Firewall misconfiguration
29.
A user sees a message saying their files are encrypted and must pay to
recover them. What is this?
A. Keylogger
B. Ransomware
C. Trojan
D. Virus
30.
The inability to open Task Manager or Regedit may be caused by:
A. Corrupt BIOS
B. Rootkit infection
C. Missing driver
D. Update failure
Answers and Brief Explanations for the 30 CompTIA A+–Style Malware Exam
✅ Malware Types (1–15)
1.
B. Trojan ✔️
Disguises itself as legitimate software but causes harm once installed.
2.
C. Worm ✔️
Self-replicates across networks without user action.
3.
B. To encrypt files and demand payment ✔️
Ransomware locks or encrypts files and demands a ransom.
4.
B. Rootkit ✔️
Designed to hide itself and other malware from detection.
5.
C. Trojan ✔️
Requires user installation; does not replicate on its own.
6.
A. Keylogger ✔️
Monitors and logs keystrokes to steal information.
7.
C. Monitor and collect user activity ✔️
Spyware tracks behavior like browsing history or clicks.
8.
B. User intervention ✔️
Viruses require execution of the host file to spread.
9.
C. Rootkit ✔️
Often loads during system boot and operates at low levels.
10.
B. Ransomware ✔️
Commonly delivered via phishing and locks data/files.
11.
C. Spyware ✔️
Adware often bundles spyware to collect user data.
12.
C. Trojan ✔️
Keyloggers are often installed via trojan software.
13.
A. Worm ✔️
Mass replication can overload networks and devices.
14.
C. Rootkit ✔️
Hides deep in the system, sometimes at the kernel level.
15.
C. Ransomware ✔️
Fake antivirus programs are classic ransomware examples.
⚠️ Symptoms of Malware (16–30)
16.
C. Malware infection ✔️
Unexpected pop-ups often point to adware or malware.
17.
C. Malware infection ✔️
Browser redirection is a hallmark of browser hijackers.
18.
C. Email account compromise ✔️
Malware or unauthorized access can cause email spoofing.
19.
B. Invalid security certificates ✔️
Malware may redirect users to spoofed or malicious sites.
20.
C. Rogue antivirus ✔️
Displays fake warnings to scare users into paying.
21.
B. Malware blocking updates ✔️
Prevents security software or OS from patching vulnerabilities.
22.
B. Unusual network activity ✔️
Spyware often sends collected data silently over the network.
23.
B. Redirected search results ✔️
Indicates browser hijacking or DNS poisoning.
24.
B. Account compromise ✔️
Often from malware stealing credentials or session tokens.
25.
B. Spyware or adware ✔️
Adds toolbars or extensions to gather data or display ads.
26.
A. Malware or driver conflicts ✔️
Malware may interfere with system operations, causing crashes.
27.
A. Adware ✔️
Often causes pop-ups and redirects to generate ad revenue.
28.
B. Malware activity ✔️
Background processes and data exfiltration slow the system.
29.
B. Ransomware ✔️
Encrypts data and displays ransom note for decryption.
30.
B. Rootkit infection ✔️
Blocks access to security tools to maintain stealth.
Stay Informed. Stay Secure.
Understanding how malware operates is the first step in
protecting yourself and your organization from cyber threats. By recognizing
the signs and knowing how to respond, you’ll be better equipped to defend
against infections—and pass your CompTIA A+ exam with confidence.
If you found this guide helpful, be sure to bookmark it,
share it with your fellow tech learners, and keep an eye out for more study
tools and security tips. The more you know, the safer your systems will be.
⚠️ Disclaimer:
This blog
post is for educational purposes only. It is intended to help readers
understand malware behaviour and support CompTIA A+ exam preparation. Always
follow your organization's IT security policies and consult cybersecurity
professionals for threat mitigation.
