A computer virus is a program capable of continually replicating with little or no user intervention. Typically, a piece of code causes damage to your computer either by deleting or corrupting files. A virus can also interfere with computer operations by multiplying itself to fill up disk space or randomly access memory space, secretly infecting your computer. Often viruses are disguised as games, images, email attachments, website URLs, shared files or links or files in instant messages.
Spyware is malicious computer program that does exactly what its name implies-i.e., spies on you. After downloading itself onto your computer either through an email you opened, website you visited or a program you downloaded, spyware scans your hard drive for personal information and your internet browsing habits. Some spyware programs contain keyloggers that will record personal data you enter in to websites, such as your login usernames and passwords, email addresses, browsing history, online buying habits, your computer's hardware and software configurations, your name, age and sex, as well as sensitive banking and credit information. Some spyware can interfere with your computer's system settings, which can result in a slower internet connection.
Adware is any software that, once installed on your computer, tracks your internet browsing habits and sends you popups containing advertisements related to the sites and topics you've visited. While this type of software may sound innocent, and even helpful, it consumes and slows down your computer's processor and internet connection speed. Additionally, some adware has keyloggers and spyware built into the program, leading to greater damage to your computer and possible invasion of your private data.
Malware is short for malicious software. Malware is a broad term that encompasses computer viruses, worms, Trojan horses, spyware, adware, and others. Malware is designed to interfere with normal computer operation, usually giving hackers a chance to gain access to your computer and collect sensitive personal information.
A worm is a type of virus that spreads through your computer by creating duplicates of itself on other drives, systems and networks. One feature that makes worms so dangerous is that they can send copies of themselves to other computers across a network via email, an infected webpage, and instant messages.
Trojan horse (Trojan)
A Trojan horse is a program that either pretends to have, or is described as having, a set of useful or desirable features but actually contains damaging code. Generally, you receive Trojan horses though emails, infected webpages, instant message, or downloading services like games, movies, and apps. True Trojan horses are not technically viruses, since they do not replicate; however, many viruses and worms use Trojan horse tactics to initially infiltrate a system. Although Trojans are not technically viruses, they can be just as destructive.
Best practices to protect against viruses, spyware, adware, malware, worms and Trojan horses
Unbeknownst to you, malicious programs can infiltrate your computer when you open an email attachment, visit certain websites, download a game, etc. To protect yourself from such attacks, it is best to educate yourself and avoid these programs all together. Check out our checklist below to learn the best practices for protecting your computer against intruders.
- Don't download files from unknown sources, including from your email or the web.
- Scan all new files with virus-scanning software before opening.
- Don't download an attachment (e.g., pictures, games, electronic greetings) unless it's from someone you know.
- Start by running anti-spyware software on a regular basis to catch any programs that may have infected your computer. After the software removes the spyware it finds, restart your computer and scan it again to make sure all spyware was deleted. Some spyware programs can be difficult to remove, so it might take more than one try.
- Be careful when downloading free or peer-to-peer files, especially music files and media sharing programs. Read the licensing agreements to understand exactly what you're downloading. Many popular applications include spyware components, and some applications won't work without those components.
- Protect your computer with a firewall, especially if you use a broadband internet connection.
- Use a trusted internet provider.
- Use antivirus software to catch viruses, worms and Trojan horses before they can do any damage.
- Don't download any programs from websites you don't trust.
- Adjust your browser's security settings to provide at least a medium level of security. A lower setting makes it easier for malware to access your computer.
- ActiveX controls are prone to spyware and other malware, so don't approve the installation of any ActiveX controls you haven't already requested.