Microsoft’s Security Response Center (MSRC) announced that there are limited and targeted attacks of booby-trapped Microsoft PowerPoint files being used to download malware into unsuspecting users.

Microsoft call this infected file as Win32/Apptom.gen and the rating given is severe. I do recall that occasionally, I will receive jokes in PowerPoint format and I believe, this is the most common way for hackers to exploit by spreading the malware via  emails attached with jokes in PowerPoint. 

While waiting for the patch to be available, one can use Microsoft Office Isolate Conversion Environment to open any .PPS or .PPT files. Essentially, what it does is, it will forced all the files (in the vulnerable older format) to be converted to XML-based file format before it is open.

Download the FileFormatConverts.exe from the MOICE link and then execute the association command as shown below.