The digital age has broken a lot of barriers when it comes to communication, and while that has been terrific for the education, entertainment, and critical communities, it's proven to be quite a challenge for the security community. Open communication can create a false sense of safety and familiarity, and that can open doors for people you'd otherwise never allow into your home. However, some simple preventative medicine (including a healthy skeptical attitude) can often be your best line of defense. When you receive emails, consider the following:
1.) Do you know the sender?
◦ Does the tone of the email match their usual style (spelling, grammar, word choice, etc)?
◦ Do you notice any changes in their normal tone?
Even if the person is familiar to you, that doesn't instantly imply safety. Some viruses can temporarily take control of a person's email system, and spam everyone in their address book with virus-ridden files. If anything in the email raises a warning flag in your mind, or if the email comes from an unfamiliar source, proceed to the second set of questions.
2.) Is the email making a request or an offer?
◦ Do you see a “call to action?”
◦ Is there an attached link or file?
Most people aren't aware of this, but many viruses cannot simply arrive in your email and begin working. In order for them to take effect, it requires some action on your part. It may be something like visiting a link provided in the email, or even as simple as opening a file attached. Please note: the file does not need to be a .EXE or other program file in order to infect your system! Viruses come in the form of many kinds of files (examples below).
.EXE, .COM, .SYS (executable files)
.ZIP, .RAR, .GZ (archived files)
.DOC, .XLS (document files)
This is by no means a comprehensive list of potentially infected files. Instead, it's an example to help you understand the mindset necessary to stay on guard: the attacks can come from unexpected places, and in fact are designed to do so. Therefore, the best defense against a virus attack is the right attitude and the right awareness. In the next installment in this two part series on how to avoid email viruses, we will examine some of the more subtle ways that people can try to take advantage of you and your computer system via your email.