A new form of spam using MP3 audio files to send a stock\n pitch has surged today. Today this audio form of spam has risen\n from being virtually nonexistant to become 10 percent of all\n spam traffic, according to several security researchers\n tracking the phenomenon.\n MORE ON MALWARE\n \n \nAudio Spam Sample (126KB)\n \n\n\n How Image Spam Works (via CSOonline.com)\n \n Who's Stealing Your Passwords? And How?\n \n PDF Spam on the Rise\n \n Four Plead Guilty to Pump and Dump Stock Fraud\n The outbreak is the latest in a string of tactics from the\n past six months which avoid filters by using file formats not\n generally blocked or difficult for filters to disassemble and\n search. It started with "image spam" which used picture files\n to bypass filters. That was followed by spam that used the PDF\n file format. Now the audio MP3 version of the spam is spreading\n rapidly.In each case, the primary use of the spam is for a\n pump-and-dump stock scheme. The message tries to entice its\n viewer (or listener) into investing in a penny stock. If enough\n recipients decide to invest, the price surges, sometimes\n doubling. The originators of the scheme then dump their shares\n at the peak price. The tactic was so effective with image spam\n that the SEC halted trading on many penny stocks to stop the\n problem.In the audio version, the user receives an MP3 file that is\n socially engineered with a name that invites\n clicking\u2014either because it is a popular band name or\n title that seems personal. Some documented titles include:\n dadsong.MP3, oursong.MP3, weddingsong.MP3, santana.MP3,\n sayyousayme.MP3, smashingpumpkins.MP3, bbrown.MP3, bspears.MP3,\n gloriaestefan.MP3, beatles.MP3; answeringmachine.MP3,\n coolringtone.MP3, listentothis.MP3 and elvis.MP3, according to\n researchers at Cyberoam, who are tracking the problem.\n The files range in size from 88KB to 150KB.When opened, the user hears a synthesized voice pitching the\n penny stock. The quality is extremely poor. Here's a sample (126KB)\n from the labs at SecureWorks, which are also tracking the\n audio spam.SecureWorks senior security researcher Joe Stewart says his\n first reaction was that audio spam, while clever, is probably\n destined for a lower success rate, both because of the poor\n quality of the audio and because of the amount of end user\n intervention required. "Who's going to open a stranger's MP3\n and listen, and what's the chance they'll repeat that action?"\n says Stewart. "With visual spam, all you have to do is glance."\n What's more, in many inboxes the visual is displayed as the\n message is selected, making it hard to avoid seeing.Still, these tactics tend to evolve from crude to\n sophisticated rapidly. Stewart acknowledges this could simply\n be a test run for a better audio spam attack in the future. He\n also notes that there didn't appear to be any malware packed\n into the audio file that would download onto a PC, but that\n "feature" could certainly be added.Also, regardless of how many people fall for it, MP3 spam\n presents a more basic problem: bandwidth consumption in\n transit. As spam evolves to take advantage of bigger files, it\n chews up more bandwidth just trying to get to its destination.\n This was a significant problem when image and PDF spam peaked,\n and researchers now report that MP3 spam is arriving as even\n bigger files than image spam.