ULTIMATE VIRUS & MALWARE PREVENTION GUIDE From Northampton Computer Repair www.northamptoncomputerrepair.com We’ve compiled a pretty good list of ways to help you stay stay virus & malware-free, each section is numbered in order of importance, to an extent. While antivirus programs are important, Windows devices now include basic virus & malware protection tools included with the OS (Windows 7 > later). No antivirus tool catches every threat in the wild and most threats are evolving in their method of distribution, making them easily missed by these programs. Macs may be more resilient to viruses, but they DO NOT come with antivirus tools preinstalled, so it is recommended to purchase or download one to be safe. Another item that should really be mentioned first AND last in order to drive home how important it is: Backups! Making regular backups of all your data is so important that it can’t be expressed just with this guide. In fact, if you haven’t backed up your data in the last month or so then stop reading this guide and do it now! We’ll wait … If you need help, we’ve created a guide for that. Part 1 of 4: Browsing Safely 1) Avoid clicking on everything. There are thousands of banner ads and popups on the internet that are designed to get your attention and make you click. Due to the way most modern browsers work, there are very few ways for you to get infected with something online UNLESS you click on it yourself. This means you should avoid clicking on banners for offers that are too good to be true. o Make sure your browser is configured to always ask before running files and downloading automatically. If you have to confirm everything, you are much less likely to get infected. o If you notice multiple download buttons, verify the correct one by hovering the cursor over each one and checking the URL it links to in the bottom left hand. Find the one that links to the URL of the site you are currently on. If the link goes to another web domain, don’t click on it. (see below) 1 2) Beware of “free” software, double-check the URL. While there are plenty of freeware and open-source programs available on the internet, always be sure of the source. If looking for a known free program using a search engine, a good practice is to avoid clicking a URL for an ad provided by the search engine (see below). Many of these ads link to bundled installers that will provide the software you want, but install much more software you don’t want, such as browser-hijacking toolbars. 2 3) Beware of misleading popups. Some of the most nefarious popups on the internet are designed to mimic the look of legitimate anti-virus software. These popups attempt to trick the user into thinking their antivirus software has found an infection. When you click the popup, however, the adware is actually installed. o Instead of clicking the warning, close the popup window and open the antivirus program on your computer. You most likely will not see any warnings. If you are still worried, run a scan using your installed software. o Don't try clicking the "X" to close the popup window, as this will usually lead to more popups. Instead, use the Task Manager to get rid of it. o Other popups may warn of an infection that only their software can fix. No legitimate antivirus company will advertise their product this way, so avoid clicking on any of these popups. o Check to ensure that your browser is configured to block popups. 3 4) Clear your cache. Popups can store information in your browser's cache, leading to them reappearing constantly. To help prevent this, clear your browser’s cache regularly. 5) Consider a different browser. If you are using Internet Explorer or an older browser such as Netscape or Safari for Windows, you may be leaving yourself exposed to security risks. Browsers such as Firefox, Chrome, and Opera are much more secure than older browsers, and more customizable. Firefox, for example, has a large array of privacy- and security-related add-ons that will help protect you online. o If you don't want to switch browsers, make sure that it is always up to date to help prevent unauthorized attacks. 6) Don't go where you're not supposed to. As viruses are illegal, they thrive on “illegal” sites. Avoid sites that let you download copyrighted content or other illegal communities. File sharing is a quick way to get infected files because many of the files being shared are copyrighted and therefore illegal to distribute. You will find that your computer is much less prone to infection if you avoid things you shouldn't be doing. o Besides viruses from files you download, many of these sites will have a litany of annoying popups and misleading advertisements. All of these could lead to virus and spyware infection. Part 2 of 4: Handling Downloaded Files 1) Be selective with your downloads. There are programs available for nearly every task you can think of, but ask yourself if you really need the program that you are about to download. Do a little research about your task; you may find that you already have a program capable of what you want to do. Downloading extra programs for every task you want to complete increases the likelihood that you'll download something malicious. 2) Download from trusted locations only. If you are downloading a program or other piece of software, it is always advisable to try to download it from the developer's site as opposed to a download service. Many of these services install their own download managers, and can infect your browser with adware. o Downloading illegal files will always be a lottery when it comes to getting viruses and worms. If you can, download from "trusted" sources in the community to reduce the risk of infection. 4 3) Look at the extension. Mischievous files often have fake extensions designed to trick you, such as ".txt.vb" or ".jpg.exe". Windows will often hide common file extensions to make browsing through your files and programs more visually appealing. Double extensions exploit this by hiding the second, dangerous extension. If you normally don't see extensions on your computer and it all of a sudden appears on a file that you've downloaded, you may have downloaded a malicious file that is hiding as something else. o To make your file extensions visible, open Windows Explorer, click the View tab/menu and select Options. Click the View tab in the Folder Options window, and uncheck the "Hide extensions for known file types" box. 4) Scan your downloaded files. If you have an antivirus program installed, you should make a habit of scanning files that you've downloaded from unknown locations. Most antivirus programs allow you to immediately scan specific files by right-clicking on the file and selecting your antivirus from the list of options. o Always scan ZIP files as these often contain multiple files in one archive. o Email programs will often scan your email files for viruses automatically, but you should still scan any downloaded files with your own antivirus program. 5) Don't open anything you don't trust completely. A virus or worm can do nothing unless you actually run the program that it is attached to. That means that simply downloading a file does not put you in any real danger. If you decide after downloading that you don't exactly trust the file, avoid opening it or delete it until you can confirm its integrity. 5 6) Read the license agreement. You know those legal documents that you always blindly accept when installing a program? Well, shady companies like to use the fact that most people skip them to sneak in clauses about installing spyware and other malicious software. Make sure to take the time to read these agreements, especially from companies that you've never heard of before. Part 3 of 4: Dealing with Emails 1) Don't download attachments from a source you don't know. Email attachments are the number 1 way that viruses and other malware get spread. You should never click an attachment or link in an email from someone you don't recognize. If you are unsure of the sender, get confirmation from them that the file is legitimate before downloading it. 2) Don't download attachments from a source you DO know unless you were expecting it. Many times people will get infected with viruses that send emails without their knowledge. This means you can receive email from trusted sources but the email itself is not trustworthy. If the writing is odd or the attachment looks off, do not click it. Verify with the person that they intended to send you the attachment you received. 3) Disable image previews. Many email applications can automatically load images for convenience, but this can leave you more vulnerable, as images can contain malicious code. You should only download the images in an email from a trusted source. o Note: Some services have started changing way email images are handled, making image loading safer. As a result, Gmail no longer disables images by default. Check with your mail provider for the best practices on their service. 4) Beware of odd emails from companies you do business with. A popular phishing technique is to copy the style of a company email and include links that look similar to the regular URL, but instead send you to a fake site ("povver" instead of "power", for example).