We have always taken the position that antivirus software is necessary but not sufficient, and is best viewed as a second line of defense against malware threats. A recent study published by the Imperva Hacker Intelligence Initiative confirms our suspicions in stark terms. According to this study, on average your antivirus software has about a 5% chance of detecting a new threat on the day that the threat is released by the bad guys. Given that as many as 100,000 new “strains” of malware are released every single day, chances are you will be easily infected if you are trusting your antivirus as the first line of defense.
The good news is that within one to four weeks after a given new threat, most antivirus products are able to detect and eliminate it. The bad news is that it’s a losing battle.
So if antivirus software is not your first line of defense, what is the best way to combat infection attacks? Good old fashioned vigilance and common sense. The vast majority of infections enter your computer through attachments or links in email. Spammers distribute millions of bogus emails daily that find new and creative ways to try to fool you into opening an infected attachment, clicking on a link to an infected web site, or getting you involved in some sort of fraudulent con game. The best defense is to be suspicious of each and every email, even if it appears to be from a company or person that you know and trust – often the “from” information is faked by the spammer through one means or another.
Never open an attachment if you can help it, particularly if it is unsolicited. If you think it is from someone you know, contact that person by phone to verify before opening the attachment.
Never click on a link in an email unless you first verify that the link is legitimate. Remember that the visible text showing for the link may be different from the actual link. In most email programs, you can see the actual link by hovering your mouse over the link (but don’t click). When you hover, the link will appear either in a small pop-up, or in the status bar at the bottom of the window. For example, this link actually goes to our home page. For example, if the email claims to be from FedEx, but you hover over the link and it reveals something strange like girlsinbikinis.com, then hit the Delete key.
Another common avenue for infection, particularly where teenagers are in the home, is by file sharing. Many people enjoy downloading “free” games, music, and software from file sharing sites. But a very high percentage of such files are infected. The best rule of thumb is to never download from file sharing sites. If you absolutely must do it, then download to a computer you don’t care about.
We have written in the past about a completely different form of attack that has gotten a lot of traction in our area – phone attacks. It works like this: you receive a phone call from someone claiming to be from Microsoft and claiming that they have detected problems on your computer. They ask you to allow them to access your computer so that they can resolve the problems for you. Once you give them access, suddenly they find all kinds of “problems” that can be “resolved” only if you pay them a fee for what turns out to be fake software. In the meantime, they have infected and hijacked your computer and can even encrypt it and hold your data for ransom. A number of our customers have received this phone call, and we’ve even gotten them here in our office.
The scam is effective because the scammers make the safe bet that everyone has at least some problems on their computer, and further bets that they will trust a caller who claims to be from Microsoft. It is far more personal than anonymously distributed spam email. The scammer is usually calling from a noisy call center, with poor phone quality, and in our experience always has an Indian accent. Needless to say, never give any information to such a caller. We recommend you tell them something like this: “I appreciate your call. Please hold on the line while I forward you to my cousin who works for the FBI and who will be able to assist you in this matter.” This will terminate the call quickly and ensure there are no further calls.
Many people ask us if using a Mac will ensure safety. Mac are not immune to attack, although viral infections are rare on that platform. But Macs are equally vulnerable to email phishing and phone scams, and increasingly are seeing other types of malware attack. As on Windows computers, your best bet is to be careful, and to always keep a backup of your data just in case.
It’s an ugly world out there, but if we are vigilant we can stay safe from all of these attacks.