🦠 Common Types of Malware
Malware can behave in different ways depending on how it is designed.
Some types rely on user actions, while others spread automatically.
The three most common methods of transmission are:
- Visiting an untrustworthy website
- Downloading a file from an untrusted source (compromised website or email attachment)
- Opening an infected file from removable media (USB drive)
🧬 Viruses
A virus attaches itself to a file or program.
When the infected file is opened, the virus runs and copies its code into other files, spreading the infection.
- Requires a host file
- Spreads when infected files are opened
- Can damage or corrupt files
🪱 Worms
A worm is a standalone program that can copy itself to multiple locations on a computer or network.
Once active, the worm spreads automatically across networks (making multiple copies of itself) without further user action.
- No host file required
- Spreads using network connections
- Can overload networks
🎭 Trojans
A Trojan is named after the Trojan Horse from Greek mythology.
Just like the wooden horse, a Trojan appears safe or useful but hides malicious code inside.
Users are tricked into installing Trojans themselves, often by downloading fake software or updates.
- Disguised as legitimate software
- Relies on social engineering
- Can give attackers access to the system
🔒 Ransomware
Ransomware encrypts files or the entire computer, making them unreadable.
The attacker then demands a ransom payment in exchange for the decryption key, which unlocks the files.
Without the correct key, the user cannot access their data.
- Encrypts files or systems
- Demands payment to unlock data
- Can cause severe disruption