What is malware?

Malware — short for malicious software — is any software intentionally designed to damage, disrupt, or gain unauthorized access to computer systems. Malware can infect computers, smartphones, tablets, and entire networks. Common types include viruses, ransomware, spyware, and trojan horses.

How does malware work?

Malware can enter your systems in many ways: through email attachments, infected websites, malicious downloads, or even USB drives. Once installed, malware can take control of your device, steal sensitive data, encrypt your files, or use your system to attack others.

The impact ranges from minor annoyances like pop-up ads to serious damage such as data theft, financial loss, and complete system shutdowns.

Common types of malware

Viruses
A virus attaches itself to legitimate files or programs and spreads when the infected file is shared or executed. Viruses can corrupt files, slow down systems, and cause data loss.

Ransomware
Ransomware encrypts your files and demands payment to restore access. It is one of the most damaging forms of malware, often spreading through phishing emails.

Spyware
Spyware secretly monitors your activity — tracking keystrokes, browsing behavior, and login credentials. This information is often sold to third parties or used for identity theft.

Trojan horse
A trojan disguises itself as legitimate software. Once installed, it gives attackers access to your system without your knowledge.

Adware
Adware floods your device with unwanted advertisements and pop-ups. While less dangerous than other types, it slows down your system and can serve as a gateway for more serious malware.

How to recognize a malware infection

Common signs that your device may be infected with malware include:

• Your computer or phone suddenly runs much slower than usual
• You see excessive pop-ups or advertisements, even when not browsing
• Your system crashes or freezes frequently
• Disk space disappears without explanation
• Unknown programs, toolbars, or browser extensions appear
• Your antivirus software stops working or gets disabled
• Unusual network activity or data usage