Outlook – Open “Dangerous” Attachments

With the rash of recent viruses using *.zip files to get past antivirus filters and bypass Outlook's attachment block, you may want to add the zip extension to the Level1Remove key to force users to save zips to their hard drive before opening or block access to zip files completely by adding zip to the Level1Add key.

Follow these steps to modify the registry and change Outlook's attachment security behavior.

1. Exit Outlook if it is running.
2. Click Start, and then click >Run. Copy and paste (or type) the following command in the Open box, and then press ENTER:

regedit

Verify that the following registry key for your version of Outlook exists.

• Microsoft Office Outlook 2007

HKEY_CURRENT_USERSoftwareMicrosoftOffice12.0OutlookSecurity

• Microsoft Office Outlook 2003

HKEY_CURRENT_USERSoftwareMicrosoftOffice11.0OutlookSecurity

• Microsoft Outlook 2002

HKEY_CURRENT_USERSoftwareMicrosoftOffice10.0OutlookSecurity

• Microsoft Outlook 2000

HKEY_CURRENT_USERSoftwareMicrosoftOffice9.0OutlookSecurity

If the registry key exists, go to next step.

If the Registry Key doesn't Exist

If the registry key does not exist, follow these steps to create it:

a.       Locate, and then click the following registry key:

HKEY_CURRENT_USERSoftwareMicrosoft

b.      Under Edit, click New, and then click Key.

c. Type "office", and then press ENTER.

d. Under Edit, click New, and then click Key.

For Outlook 2007, type 12.0, and then press ENTER.
For Outlook 2003, type 11.0, and then press ENTER.
For Outlook 2002, type 10.0, and then press ENTER.
For Outlook 2000, type 9.0, and then press ENTER.

f. Under Edit, click New, and then click Key.

g. Type "outlook", and then press ENTER.

h. Under Edit, click New, and then click Key.

i. Type Security, and then press ENTER.

4. Under Edit, click New, and then click String Value.
5. Copy and paste (or type) the following name for the new value:

Level1Remove

6. Press ENTER.
7. Right-click the new string value name, and then click Modify.
8. Type the file name extension of the file type that you want to open in Outlook. For example:

.exe

To specify multiple file types, use the following format:

.exe;.com

9. Click OK.
10. Exit Registry Editor.
11. Restart your computer.