Unfortunately, the world of the Internet is coming to resemble the Wild West these days. Crooks and thieves are everywhere and the damage they are doing to our computers is becoming truly significant. I end up getting more business from it but I would much prefer to be paid for preventive measures, rather than for cleaning up damage. This bulletin is to point out yet another step you can take to avoid potential damage to your system.
You have no doubt read that you should never "open" an email that you are suspicious of or don't recognize. In spite of anti-virus programs which scan incoming emails, this still remains good advice. All the fancy features (photos in the text of the message, fancy fonts, emoticons, etc.) of modern emails are created by imbedding executable code into the message. When you "open" the message, this imbedded code gets executed, producing your fancy images. The bad guys take advantage of this and imbed the code for their viruses in emails disguised to look innocent to you. Open one of these emails and bingo, the bad code executes and infects your computer. Good practice says, always look twice at suspect emails and delete them unopened when in doubt. I thought I was doing that.
Here's the problem -
Until recently, I have always run my Outlook program's main screen with two panes, upper and lower. The upper pane would display the list of newly-arrived emails in my Inbox, while the lower pane was the "preview pane". For whichever email I had selected in the upper pane, the lower pane displayed the beginning few lines of the enclosed message. Most email programs have some form of this feature. It turns out that in order to display the "preview", the email gets opened internally! To the user, it doesn't look the same as fully opening the email, but it is. If an incoming email contains a virus, just the act of viewing the first few lines in the preview pane, has opened the email. It doesn't need to be opened full screen to have the virus install itself.
Turn off the Preview Pane -
My advice is, turn off the preview pane in any folder which receives unopened email. For many of you, that will be the Inbox only. For people who use "Rules" to automatically file incoming email into separate folders, you should consider turning off the preview in those folders as well. (They aren't quite as bad usually, only because emails filed by Rule are from sources known to you. Still, some viruses spread themselves by broadcasting to a friend's email address book. If your friend is not running an anti-virus program and is not scanning outgoing email, you could still receive an infected email from him or her.)
How do you turn the Preview Pane off?
In Outlook, for example, preview panes are turned on and off by individual folders. Let's start with the Inbox folder. With the Inbox selected, click on View on the Main Menu. On the View menu, look for an icon for Preview Pane. It toggles the Preview Pane on and off. Incoming emails will still be listed with their subject lines showing, but the preview won't be shown. This at least gives you a fighting chance to decide which ones are legitimate, and which are questionable. If you aren't sure about an incoming email, call the person and ask if they really sent it.
I truly don't mean to be an alarmist, but the virus world is becoming more complex and I'm trying to keep you a step ahead.