services statistics projects policies software support resources staff contact us NSG home UofT home

UTORmail: Virus Filtering and Renaming Attachments (Win) Here is the scenario: you are expecting a legitimate attachment from a colleague or friend outside of the UTORmail system*. Unfortunately, the attachment bears one of the extensions listed on your right and will trigger the anti-virus filter to action. To prevent the attachment from being detected and removed by the filter, you will need to ask the sender to rename the attachment before sending it. Once you receive the message with the renamed attachment, you will need to rename it again in order to view it. For example, your colleague wants to send you a file called filename.zip. She will need to rename filename.zip to avoid the anti-virus filter. The easiest way to rename a file is to add an extra three letter extension. The extra letters must be different than those extension names on your right. Using this guideline, your colleague might add 'bbb' to filename.zip so that the file becomes filename.zip.bbb. In its renamed state, filename.zip.bbb will fly past the anti-virus filter undetected and arrive intact in your Inbox. Once you receive the message with the filename.zip.bbb attachment, you will need to rename it to filename.zip in order to view. "How is all this accomplished?" you may ask. Instructions for renaming a file as both sender and recipient follow. But first, there is a trick of which you need to be aware. In order to rename files in Windows, you must first be able to see the full file name including the extension. Windows has a feature that allows you to hide extensions from view. Below are instructions on how to view extensions for all supported Windows operating systems. How to view extensions in Windows XP, Windows 2000 and Windows Me 1. Start the Windows Explorer Start -> Programs -> Accessories -> Windows Explorer. 2. Modify the Folder Options to allow you to view extensions Tools -> Folder Options -> Select the View tab. Under Advanced settings: There should not be a checkmark beside "Hide extensions for known file types". Press OK to save changes. How to view extensions in Windows 98 1. Start the Windows Explorer Start -> Programs -> Windows Explorer. 2. Modify the Folder Options to allow you to view extensions Tools -> Folder Options -> Select the View tab. Under Advanced settings: There should not be a checkmark beside "Hide file extensions for known file types". Press OK to save changes. How to view extensions in Windows 95 1. Start the Windows Explorer Start -> Programs -> Windows Explorer. 2. Modify the Folder Options to allow you to view extensions View -> Options. There should not be a checkmark beside "Hide MS-DOS file extensions for file types that are registered". Press OK to save changes. Instructions for Renaming (Sender): How to rename a file by adding an extra extension The advantage of adding a second extension versus renaming the original extension is that the recipient will know which program created the file. This will help the recipient to know which program should be used to view it. NOTE: These steps must be done before the attachment is sent. 1. Go into the folder that contains the attachment file. 2. Select the file by right clicking on it once. 3. Select Rename from the menu. 4. The entire filename will be highlighted. Place the mouse cursor at the end of the file. It should be just after the extension 5. After the original extension, type in a dot and three characters that don't create one of the extensions to be filtered (e.g. bbb). Press the Enter key. 6. Press the YES button on the Rename confirmation window to save the renamed file. If you made a mistake, press the NO button and go back to step 2. 7. Your filename should now look similar to this: filename.ext.bbb Instructions for Renaming (Recipient): How to rename a file by removing an extra extension NOTE: These steps must be done after you save the attachment. Remember to run a virus scan on all saved attachments before you open them. 1. Go into the folder that contains the attachment file. 2. Select the file by right clicking on it once. 3. Select Rename from the menu. 4. The entire filename will be highlighted. Place the mouse cursor at the end of the filename. It should be just after the second extension. 5. Backspace until you remove the characters ".bbb", without the double quotes but including the dot, and press the Enter key. 6. Press the YES button on the Rename confirmation window to save the renamed file. If you made a mistake, press the NO button and go to step 2. 7. Your filename should now look similar to this: filename.ext Instructions for Renaming (Recipient): How to rename a file by removing the extra extension using email software You have received an email with an attachment that the sender has renamed filename.ext.bbb. This file must be renamed before viewing. NOTE: Run a virus scan on all saved attachments before you open them. 1. Save the attachment into a local folder using your email software. 2. When saving you will have an opportunity to rename the file. Remove the second extension ".bbb" before pressing the Save button. The new file name will be filename.ext. This should now allow you to view the attachment file with the software which created it, but only if you have the same software installed on your computer. *Only messages from other post offices are filtered. Messages sent from one UTORmail customer to another using a campus network connection or UTORdial are NOT filtered. If, however, you are a UTORmail customer and use an Internet Service Provider external to the University (i.e. Sympatico, Rogers, etc), any attachments sent to another UTORmail customer will travel through the anti-virus filter. Take me back to the top so that I can continue reading. Extensions that will be filtered: .ace .ade .adp .bas .bat .chm .cla .class .cmd .com .cpl .crt .cs .eml .email .exe .hta .inf .ins .isp .js .jse .lnk .mde .msc .msi .msp .mst .ocx .pcd .pif .reg .scr .sct .shs .shb .vb .vbe .vbs .wsc .wsf .wsh