Scan questionable e-mail attachments

Question

During your radio show you mentioned a site that would check attachments for viruses. I was in the car and couldn't write the site down. Could you please tell me the name of the sight and instruction for use?

-Lorrence

Answer

This question was answered on August 8, 2008. Much of the information contained herein may have changed since posting.

Just about everyone that provides assistance to computer users barks out the same command, over and over again: DON’T OPEN FILE ATTACHMENTS!

While as a general piece of advice it is very sound, as a practical matter, it really doesn’t address some real world situations.

Legitimate attachments can come to us every day, so what can the average user do if they think that an attachment is something that they want to open?

In general, if someone you are corresponding with says that they are going to send you an attachment or a business colleague sends you a spreadsheet or document with clear indications of a current discussion that you’ve been having, chances are that the attachment is legit.

The problem with giving blanket guidance is that there are always exceptions, which all can’t be covered in the space or time allotted.

In the case of attachments, all it takes is one rogue file that you open that you shouldn’t have and the damage is done. Most malicious code will appear in your Inbox with a “spoofed” address, which means it did not actually get sent from the address in the “From” section.

If they can get you to let your guard down for even one second by making it look like it came from someone you know, they might trick you into opening the attachment.

Today’s malicious code is quite capable of overpowering, sidestepping or even disabling your anti-virus program if the bad guys can get you to open certain types of attached files.

For those situations where you believe an attachment is legit, but you are not absolutely sure, you can get a free “second opinion” before opening the file.

A website called VirusTotal.com offers to scan any file by over 35 different virus scanning engines from all the major anti-virus companies and a whole host of smaller companies that have created specialty anti-virus detection systems.

You can have a file checked in two ways: Go to www.virustotal.com and upload any file you want checked (which means you will have to save the attachment to your local hard drive first) or forward any message that has an attachment (cannot exceed 10 Mb in size) to scan@virustotal.com and replace the subject line with the word “SCAN”.

If you upload the file, you will get an onscreen report from all of the various anti-virus scanning engines or if you forward an e-mail with an attachment, you will get a detailed report e-mailed back a short time later.

The detailed report will show if any of the anti-virus engines detected anything and if they do, there is a link at the bottom that will give you more information about what the malicious code does.

CAUTION: If the contents of any files to be scanned contain very sensitive personal or company information, you may not want to use this service as any file uploaded or e-mailed has the potential of being accessible by those that work with and around this project.

Author

Posted by Ken of Data Doctors on August 8, 2008

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