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Information Technology
Member, Texas Tech University System The Princeton Review - 373 Best Colleges, 2011 Edition

Blocking of Unsafe Attachments

To help prevent widespread infection used by many of the more common viruses, ASU has setup attachment blocking on the ASU email server to protect all users. There are some attachments delivered in emails that may contain malicious data and are potentially dangerous. Many viruses use email to deliver a copy of the virus to email users in order to try to infect others.

What attachments have been blocked?

The following table contains the list of extensions and attachments that are blocked by the ASU email server. An extension is the 2-3 letters at the end of a filename following a period (for example, the file HOMEWORK.DOC has an extension of DOC). As security risks are assessed, other attachment types may be added to this list at any time without notification.

  • FileName *.ade
  • FileName *.adp
  • FileName *.app
  • FileName *.asx
  • FileName *.bas
  • FileName *.bat
  • FileName *.chm
  • FileName *.cmd
  • FileName *.com
  • FileName *.cpl
  • FileName *.crt
  • FileName *.csh
  • FileName *.exe
  • FileName *.fxp
  • FileName *.hlp
  • FileName *.hta
  • FileName *.inf
  • FileName *.ins
  • FileName *.isp
  • FileName *.js
  • FileName *.jse
  • FileName *.ksh
  • FileName *.lnk
  • FileName *.mda
  • FileName *.mde
  • FileName *.mdt
  • FileName *.mdw
  • FileName *.mdz
  • FileName *.msc
  • FileName *.ps1
  • FileName *.ps1xml
  • FileName *.ps11
  • FileName *.ps11xml
  • FileName *.ps2
  • FileName *.ps2xml
  • FileName *.psc1
  • FileName *.psc2
  • FileName *.msi
  • FileName *.msp
  • FileName *.mst
  • FileName *.ops
  • FileName *.pcd
  • FileName *.pif
  • FileName *.prf
  • FileName *.prg
  • FileName *.reg
  • FileName *.scf
  • FileName *.scr
  • FileName *.sct
  • FileName *.shb
  • FileName *.shs
  • FileName *.url
  • FileName *.vb
  • FileName *.vbe
  • FileName *.vbs
  • FileName *.wsc
  • FileName *.wsf
  • FileName *.wsh
  • FileName *.xnk
  • ContentType application/hta
  • ContentType x-internet-signup
  • ContentType application/javascript
  • ContentType application/x-javascript
  • ContentType text/javascript
  • ContentType application/prg
  • ContentType text/scriptlet
  • ContentType message/partial
  • ContentType application/x-msdownload

How do I send one of these file types?

There are two ways that you can send a normally blocked attachment. You can either compress (zip) the attachment or rename it.

Compress File – Compressing the attachment is useful if the file is large. Compression shrinks the file and allows it to be sent faster. Since compressed files (such as ZIP files) are not blocked, these can be sent safely to others. To do this, a program such as WinZip will need to be used by both the sender (to compress the file) and the receiver (to uncompress the file).

Rename File – Renaming the extension of the file allows the attachment to completely bypass attachment blocking. For example, renaming the file HOMEPAGE.URL to HOMEPAGE.ASU and then sending the renamed file as an attachment will allow it to go through. The receiver will then need to save the file and rename it back to its original extension so that it functions as normal.