Update: Graham Cluley at Sophos has also blogged about this email variant, with some additional detail.

A new variant of the “Do [Something Important] by opening the attached file” scam has arrived. The goal is to trick you into running the malware that is attached. While most Antivirus software will detect and prevent you from running known malware, 100% accuracy is impossible, and new malware variants may not be detected whey they have just been released. Here’s what the email looks like:

Subject: The police investigation is under way now. You’ll be really sorry about what you have done.
Hello there
Do you know who posted these photos online?? This is strange cause there’s your FB acc there. Why did you do it and how did you get my photos?? This is a crime actually do you know?? I put one photo in attachment. We have to clear this thing or else I’ll have to contact my lawer!