“There’s been an upsurge in ASCII spam in the last week…It’s quite effective in getting through filters,” said Chris Boyd, director of malware research at messaging management firm FaceTime Communications.

But earlier efforts to use ASCII art for spam have proven to be duds, he added. “The downside is that 9 times out of 10, it’s completely useless because it’s almost impossible to read, or it’s a really bizarre picture of a naked lady that’s not clickable,” Boyd said.

Evasive maneuvers

Spam filters can detect the word “Viagra” and suspect Web addresses of sites trying to get rich quick by catering to the demand for the drug. But it’s another thing altogether to detect an ASCII art version of the same word. Indeed, an ASCII art spam e-mail reading “Viagra-$1.15” and “Cialis-$1.99” made it past the spam filters of my Yahoo Mail and Gmail accounts.

Google declined to comment specifically on ASCII art spam. “We expect spammers to use every means possible to try to send spam. That’s why we have a very robust spam-fighting effort at Google,” the company said in a statement. Yahoo didn’t respond to a request for comment.

Here’s why it’s clever. One line of the e-mail is “78 46 60 11 04 75 300 38 0348 18 61 55171″–gibberish that hardly resembles part of the word “Viagra” or a suspect URL. But reading it on my screen as part of the overall text, its meaning was clear to me in a flash. And a spam generation program could evade spam filter fingerprinting by randomly substituting other numbers into the text art.

© CNET.com

ooooo          .oooooo.   ooooo        oooooooooooo   .oooooo.
`888'         d8P'  `Y8b  `888'        `888'     `8  d8P'  `Y8b
 888         888      888  888          888         888
 888         888      888  888          888oooo8    888
 888         888      888  888          888    "    888     ooooo
 888       o `88b    d88'  888       o  888       o `88.    .88'
o888ooooood8  `Y8bood8P'  o888ooooood8 o888ooooood8  `Y8bood8P'

Joerg Seyfferth’s ASCII text generator