Sophos researchers recently came across spam e-mails claiming to come from Groupon, which include malicious attachments.

"Emails allegedly from Groupon, with the misspelled subject line of 'Groupon dicount gifts,' claim that one of your friends has shared a Groupon deal with you. Except they probably haven't," writes PCMag.com's Stephanie Mlot. "'Now Groupon.com gives an opportunity to share a discount gift with a friend!' the spelling-challenged email reads. 'Enjoy your discount gift in the attachement and share it with one of your friend as well.'"

"Attached to the emails is a file called Gift coupon.zip, which contains a Trojan horse designed to infect Windows computers," writes Sophos' Graham Cluley. "Sophos products detect the malware as Troj/Bredo-ABB and Mal/BredoZp-B. As always, keep your anti-virus up-to-date and your wits about you. It's easy for anyone to make a professional-looking email using the branding of a well-established website in their attempt to lure you into opening an attached file or clicking on a dangerous web link."

"If the poor spelling doesn’t automatically tip you off to some shady activities, the fact that the email wants you to download an attachment should," writes WebProNews' Josh Wolford.