From UPS.com:

UPS has become aware that a unknown third party is sending out emails that somewhat resemble a genuine UPS message. These emails are not from UPS. The message leads the recipient to believe that a UPS shipment could not be delivered. The recipient is then advised to open an attachment containing a waybill or invoice for the shipment to be picked up.

We have investigated some of these SPAM messages, and verified that the email attachment did contain a virus.

We recommend that you do not open the email attachment as it may contain a virus. We also recommend that you delete the email immediately. While UPS does send official notification messages to our customers, rarely do they include attachments.

We take our customer relationships very seriously at UPS, and I apologize that you received one of these emails.

Please contact us if you need any additional assistance.
UPS Customer Service