Blocked Attachments

In order to limit the possibility of viruses being spread by email, we block certain attachments. This helps address the delay between a new virus appearing and conventional anti-virus software being able to detect it.

With the change to Office 365 we are no longer blocking macro enable Word (doc), Excel (xls) and PowerPoint (ppt) files.

The file types currently blocked are those with any of the following extensions:

Blocked Attachments:
ACE

ADE

ADP ANI  APP             
BAS BAT                  
CHM CMD COM CPL CRT            
DLL DOCM   DOS                
EXE                    
HLP HT HTA                 
INF INS ISP                
JAR JOB JS  JSE               
LNK                    
MDA MDB MDE MDL MDT MDW MDZ MSC MSI MSP MST
OBJ  OPS  OS2                
PCD PIF PRF PS1  PPTM             
RAR REG                   
SCF SCR SCT SHB SHS            
URL                    
VB VBE VBS                
WSC WSF WSH W16               
XLSM
ZIP files containing any blocked attachments                    

If an email with a banned attachment type comes into the university from an external source, the attachment will be replaced by a warning message and the email forwarded to the recipient. No warning is passed back to the sender.

Sending and Receiving Blocked Attachments

Where you have a genuine need to send or receive a program or document that is being blocked we recommend that it be shared using our owncloud service

Attachment File Extensions

Attackers have attached viruses with seemingly harmless filenames to email messages. Some computers are configured by default to hide filename extensions and attackers will try to take advantage of this and mask the .exe file by giving it a fake extension to make an executable file look like a simple document or text file. If your file extensions are hidden you would see only "filename.txt" or "filename.doc" and could mistake it for a harmless file. With the ability to see file extension, the file would read "filename.txt.exe" or "filename.doc.exe." Attackers may even deceive you by having the virus behave as you would expect, while it is really attacking your computer. To help avoid this, make sure that your computer shows all file extensions.

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