Malware: The Many Faces of Malicious Software

The 30-second explanation

Malware is unwanted software that does something you did not agree to: stealing information, locking files, spying, or handing control of your computer to someone else.

How it works

1. 1

   1. Delivery

   An attachment, download or unpatched flaw brings it in.

2. 2

   2. Execution

   The code runs, often disguised as something normal.

3. 3

   3. Persistence

   It sets itself up to survive a reboot.

4. 4

   4. Objective

   It steals, spies, spreads or locks.

Malware needs to get onto a device first. Common routes are a fake attachment, a dodgy download, a malicious advert or an unpatched flaw. Once running, it does its job: a trojan pretends to be useful, an infostealer copies saved passwords, ransomware locks files, a worm spreads itself, and a remote access tool lets an attacker drive the computer. Good defence combines updates, cautious habits and software that watches behaviour.

Real-world example

How to spot it

• Software from unofficial sources

  Cracked or 'free' versions of paid programs are a favourite hiding place.

• A device that suddenly slows down

  Unexplained high CPU use or new programs at startup.

• Security tools turned off

  Malware often tries to disable protection.

• Unexpected pop-ups or new browser extensions

  Things you did not install.

What to do

1. 1Install software only from official sources, and keep the system and apps updated.
2. 2Use reputable endpoint protection and do not switch it off to run something.
3. 3If you suspect infection, disconnect from the network and get help before entering more passwords.