Here’s a good reason to pay for and remember to update your Microsoft Office software. Researchers at Kaspersky Labs and elsewhere are describing  two or more pieces of malware that can secretly steal confidential data from Macs.

The malware, called SabPub, arrives by means of an infected Microsoft Word document–using a vulnerability for which Microsoft had offered a patch in 2009, but that many people hadn’t installed, possibly because they were using pirated versions. The new finding comes just two weeks after security researchers confirmed that more than 500,000 Macs had been infected by malicious software, or “malware,” known as Flashback, arriving through a Java vulnerability.