'Image spam' could bring the internet to a standstill
Last updated at 11:52am on 10.01.07
At first, they seem like your average junk email, containing share tips or an advertisement for Viagra, along with a small, slightly garbled picture.
But this, experts say, is the spam that could bring the internet to a virtual standstill this year.
To bypass anti-spam software, the emails use an image instead of text.
In the past six months, this "image spam" has seen a massive increase and now represents 35 per cent of all junk email, according to security software firm F-Secure.
Mikko Hypponen, chief research officer, said: "Image spam is taking up 70 per cent of the bandwidth bulge on account of the large file sizes every single one represents."
The emails, generally containing stock tips, come from gangs and even bored teenagers in the United States and Russia trying to inflate prices in a swindle called "pump-and-dump".
They promise that a cheap, usually American, stock will take off. The perpetrator then dumps his stock as buyers leap in before it collapses.
Dmitri Allperovitch of computer security company CipherTrust said: "They're niche companies with no profit and no products, so when you see a spike from almost no trades to two or three million when the spam is sent out, you know there were a lot of people who fell for it."
Researchers believe hackers have targeted the recipients of computers at Christmas and are using these machines. Most spam is sent by "botnets" - machines hijacked by hackers to send out email on their behalf.
Some researchers estimate about 10 per cent of the world's 650 million online computers are botnet victims. They say this year has already shown just how large the networks after one of the biggest crashed, resulting in a 30 per cent fall in spam for the week it was disabled.
Diego d'Ambra of email monitors SoftScan said: "For years spam has just been steadily going up. A major botnet was almost certainly the cause of the fluctuation since botnets are now the single biggest factor in spam generation."
In the most notorious case so far, Jonathan Lebed, 15, from New Jersey, was prosecuted in 2000 for failing to disclose an interest in the shares he was promoting in chat rooms.
Lebed agreed to pay $285,000 (£150,900), which is thought to be significantly less than he made.
He claims to have gone legitimate with a stock-picking website.
Reader views (9)
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One way to stop image spam is to only accept plain text e-mails.
- Matthew, Missouri, USA
Strip images at the backbone level. Maybe ISP's will need to cap the amount of data sent via smtp per hour on non-commercial accounts and force commercial accounts to take responsibility for their poor security on workstations.
- John, Penticton, B.C. Canada
I get some of these image spam messages from time to time. I throw them in the trash and don't worry about them. One reason that I don't get too many of them is that I don't give out my email address willy-nilly. I used to work in a public library computer lab. I would see patrons posting their email addresses in chat rooms and on message boards. Then they would ask me why they were getting hundreds of spam emails every day. I tried to explain it to them, but I guess there's a reason why they were using library computers rather than having their own.
- Ollie, Joplin, MO USA



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