Zipped Files Can Zap Antivirus Apps - Can Email Survive?

PCWorld explains the current trend of virus writers using zip files to hide payloads and, as a consequence, PC Magazine asks whether email can survive:

While .zip files were occasionally used to mask virus payloads, the practice wasn’t common in virus writing circles because .zip, unlike .scr and .pif files, required separate software to be installed on the receiving system before the files could be opened and run on ubiquitous Windows machines, he says. All that changed with the release of Microsoft’s Windows XP operating system, which includes native support for opening .zip files. That allows virus writers to count on users being able to unzip their attachment and open the virus file stored inside, Shipp says.

. . . "Security is always a trade-off," says Cloudmark’s Prakash. "You can’t just stop receiving .exe and .zip files from people, because most of them are useful." Companies need to balance business needs with security when setting up policies for files like .zips, he says. Security policies that attach a trust level to certain e-mail senders outside and inside the company could be effective at blocking malicious .zip attachments. Better user education that addresses bad habits like forwarding executable attachments could also help, Prakash says.

PCWorld
Zipped Files Can Zap Antivirus Apps
Compressed folders can hide worms, viruses, and more, experts warn.

It was the exclamation point on the gradual rise of mass-mailing viruses. This year, MessageLabs says, the ratio of virus-infected messages to other e-mail traffic increased by nearly 85 percent. As if all those SoBig messages weren’t annoying enough, it was soon apparent that the virus was reprogramming PCs to serve as "open relays," giving spammers still more launchpads for their anonymous attacks. MessageLabs claims that more than 66 percent of all spam is now sent using systems commandeered by SoBig or MiMail, a similar worm.

PCMag
Can Email Survive?