The second reason became known recently. The US CERT Coordination Center (CERT / CC) conducted a survey that showed him dangerous way with which Office for Mac 2011 handles one forgotten macros format (XML), when integrated into SYLK (SYMBOL LINK), a Microsoft file format used for sharing data (mainly spreadsheets).
Many users may not have heard of either format. After all, there are many forgotten formats from the past, but they are still supported today. software. The hackers often take advantage of their ignorance users and use these formats to attack.
Last year, some Dutch researchers reported that the SYLK .slk file format could be used for Mac infection computers.
Despite the researchers' warning, the Office did not send alerts security users when they were trying to open a file that had this format.
One solution would be to enable all macros or deactivate after notification is displayed, which stops running macros automatically, but informs the user every time he has to intervene.
Many would think that automatically disabling all macros (without alerting the user) would be the safest solution. However, in this case, turning off macros with a notification is the only option warns of a malicious XML / SYLK file.