How Anti-Virus Programs Work:
Anti-Virus programs (also called anti-malware, virus scanners or end-point protection) are programs that help prevent your computer system, mobile phone, or tablet from becoming infected with malware.
Most anti-virus programs work by comparing (a.k.a. scanning) files against a database of known types of malware. Because malware is continually being developed by cyber-criminals, the database needs to be updated in order to identify new types of malware. The database is updated by downloading periodic updates called "definition files". If you are using a subscription based anti-virus program, and you let your renewal lapse you will stop receiving these "def file" updates. This means your system and files will be vulnerable to new types of malware.
Real-Time scanning and on-demand scanning:
- Real-time scanning is the most important component of the program because it checks each file as it is downloaded, opened, copied or modified. This is the first line of defense from malware and it is important that the real-time scanning feature is always enabled and running as it can stop malware from infecting your system. Become familiar with your anti-virus program and on where the real-time scanning settings are.
- On-demand scanning is another important component that can be scheduled or setup manually to scan every file on your device for malware. You may have downloaded malware before there was a definition file that could detect it. Running full scans periodically can detect malware that the real-time scan was not able to detect previously. Become familiar with your on-demand scanning settings and schedule or run full system scans at least once a month.
Pros and Cons of anti-virus programs:
A good anti-virus program is absolutely essential for your computer (and yes that includes MAC systems). However for it to be effective, it must be able to get definition files on a daily basis (hourly is better) and the real-time scanning feature must be active and enabled.
The downside is that because anti-virus programs primarily rely on comparing files to known viruses.. when a brand new virus is "released into the wild" it can take hours and sometimes days for the anti-virus program to be able to recognize it as harmful malware. For this reason, do not rely on your anti-virus program alone to detect "bad" files. You must use your judgement and be cautious about opening files and email attachments. Even when they come from someone you know, be careful. Email accounts and web pages are frequently hijacked to take advantage of your familiarity with the source to get you to open and run infected attachments and downloads.
Getting a second opinion, VirusTotal:
A good resource you can use if you aren't sure if a file or weblink is "good", is to check it against VirusTotal. VirusTotal is a project managed by a consortium of groups that takes a file you upload to their website and scans it using multiple commercial anti-virus programs. Still not a foolproof guarantee that the file is safe, but this is a great resource for checking files and weblinks. Their website is at virustotal.com
Anti-virus solutions for Windows based computers:
Starting with Windows versions 8 and 10, Microsoft provides a free and full featured anti-virus solution called Windows Defender. Users with Windows 7 may have a version of Windows Defender that is not full featured, and will need to add Microsoft's "Security Essentials" program (available for free from Microsoft's website) to have real-time protection. Windows versions older than 7 will require a third party anti-virus solution. BitDefender and MalwareBytes provide endpoint protection products that are some of the industry leaders in real-time detection of malware.
Anti-virus solutions for Apple iOS based computers:
While malware for MACs is not as common as with Windows, your Apple based system is not immune to specifically crafted ransomware and viruses. Avira and Malwarebytes are vendors that offer free anti-virus programs for your Mac OS based system.