Warning! Yet another Fake UPS Failed Delivery Notice

Warning! Fake Failed Delivery Infected MessageJust received yet another email alledgedly from UPS, but of course it isn't from the genuine company, but another attempt to fool people into downloading infected files!

With a subject of Delivery halted for shipment #654308

The email starts off with:

Dear customer,
Our courier has attempted to deliver your package today, but nobody answered the door at the destination address.
The shipping process has been interrupted and the package was delivered to our local office.
A delivery notice was left in your mailbox.
To reschedule the delivery, please call us and confirm the information on the delivery notice.

And ends with a link which encourages you to download the delivery notice which is in fact a spoofed link to an infected self running file (.exe) which will infect your computer with malware or worse still, encrypt your files requiring you to pay a large fee in the hope of recovering your data.

What is Ransomware?