Virus: A virus is a software program which can destroy hardware and software.
Worm: A virus which is sent by an email attachment is known as worm. A virus cannot be sent via text in email. It has to be an executable file as an attachment.
Macro virus: A micro virus is a program that uses word processor program or a spreadsheet program to run.
Trojan horse: A trojan horse is a program which installs itself on the computer. It then sends sensitive information like passwords and other important data by accessing your computer.
Denial of service attack: A trojan horse program is used to take over the host computer and then it bombards the server with sending multiple requests for accessing information.
Here are the ways by which you can safeguard your computer from virus, worm, trojan horse, denial of service attacks:
1) Install an antivirus program like Kaspersky or McAfee. Using the full version will provide you with extra protection. These programs also run in the background to check for vulnerabilities in your system.
2) You can check regularly whether the installed antivirus is working fine. It will show a message like “Your computer is protected”.
3) Whenever you are downloading a file, your antivirus program will alert you with probable threats. Make sure you act accordingly.
4) Scan external hard drives, pen drives, and other CD and DVD ROMs before opening. You don’t have to worry about it doing it manually. Most antivirus programs do that by default whenever you connect any of these devices to your computer.
5) You should scan an email attachment before downloading.
6) Fishy email attachments should not be downloaded at all.
7) By using a firewall: A firewall is used to control passing of information from one network to another by controlling the ports. It also controls outgoing and incoming packets. Most internet security software comes with a powerful firewall.
8) Always download softwares and other files from a trusted source.