Some of us deal with a plethora of PDF documents. Perhaps we need to make various edits and comments to the documents, or maybe we need to convert the PDFs into a different format like a Word document. Unfortunately, depending on the sources that we acquire our PDFs from, some of the files may in fact be secured, meaning no edits or changes can be allowed on the document for content integrity reasons.
What's JailbreakMe? It's an easy way to jailbreak an Apple iOS device using a PDF (related) vulnerability. It's done with a "drive-by" style exploit.
All somebody needs to jailbreak their (newer) iPad/iPhone/iPod is to visit jailbreakme.com and to touch the free/install button. The German Federal Office for Information Security has issued a warning about this. They're concerned about the potential for targeted malicious attacks using trojanized versions of the JailbreakMe exploit.
We've seen it time and time again: someone sends an employee an email with a malicious attachment, they open the attachment and all hell breaks loose soon thereafter.
One enabler for this type of attack is widely used, bloated, buggy software. Opting instead for small (not many bells and whistles), unpopular software makes you safer. This is especially important when dealing with files from strangers (and any file attached to an email message should be considered coming from a stranger).