It is important to remember that macro-enabled workbooks can hide nasty viruses that can seriously damage your computer files. When receiving a workbook that is macro-enabled off another person (either via email or the Internet) your first consideration should always be security. The security settings in Excel will allow you to open and edit the workbook, but the macros will NOT work.[/font]
There are 4 levels of security that can be set to prevent any damage from infected files:
Disable all macros without notification: All macros in the workbook will be disabled upon receipt and you will not be made aware that they were there at all.
Disable all macros with notification: This option shows you all the available macros and you have the choice to enable them or not.
Disable all macros except digitally signed macros: A digital signature confirms that the macro originated from the person/organization that has signed it and has not been added to or altered in any way. There are 2 main ways that a digital signature can be obtained – from your security administrator or a self-signed certificate from a trusted computer. This is the recommended level.
Enable all macros: This option is not recommended as it can lead to problems with viruses. It allows any hidden ‘nasties’ straight into your computer and your valuable files.
Setting your macro security level
Once you have decided which level of security is appropriate under the circumstances, you will then need to set it on your computer:
. Click the Developer Tab , which can be found within the Ribbon
. Click the Macro Security button, found in the Code group
. This will display the Trust Center Dialogue Box – choose your required level of securityClick OK
The required security level has now been set and you no longer have to worry about introducing unwelcome bugs and viruses onto your PC.
Choosing to enable macros
If you are sent a workbook that has macros (and if your chosen level of security allows) a message will appear in the Information bar, advising that macros have been disabled and an Options button
If you are sure you trust the source of the workbook and you want to enable them, click the Options button to display the Microsoft Office Security Options dialogue box: this explains the risk of accepting files with macros from unknown sources and has the following options.
1) To keep macros disabled:
. Choose the Help protect me from unknown content option
. Click OK
2) To enable all macros:
. Choose the option that says Enable this content
. Click OK
It is highly recommended that great care is taken when accepting and opening workbooks with macros in them. We are constantly warned about opening attachments from unknown sources or clicking on links to an unknown destination, so please give the same consideration when deciding whether to enable macros as they can potentially hide just as much danger.