Malware and Antivirus Software

Malware is a program created to harm a computer, steal data or take control of a device without the user knowing. A virus copies itself into other files and spreads when the user opens an infected file. A worm spreads through a network on its own, without any person’s help, and a trojan gets in disguised as a useful program and does hidden harm.

There are other dangerous kinds. Spyware watches what the user does and steals passwords. Ransomware encrypts files and demands money to unlock them. Adware keeps showing advertisements. An infected computer runs slowly, opens windows by itself and loses files.

Malware most often spreads through “free” copies of paid programs from doubtful sites, files attached to emails, unknown flash drives and links in social networks. Phishing is a way of tricking people into giving a password or card details through a fake site or message. Messages like “You have won a prize” are almost always a fraud.

Antivirus software finds and removes malware: it compares files with the “signatures” of known viruses and watches for suspicious behavior. Rules of protection: update the antivirus and the system regularly; download programs only from reliable sources; do not open links and files from unknown emails; keep backup copies of important files. An antivirus cannot protect from everything; your own caution is the main defence.

Key takeaways

• Types of malware: virus, worm, trojan, spyware and ransomware.
• A worm spreads over a network by itself, while a trojan arrives disguised as a useful program.
• Phishing means tricking people into giving data through a fake site or message.
• Key rules: update the antivirus, download from reliable sources and keep backups.