Symantec's holiday spam listing is seeing an increase in threats which capitalize on the concept of a trusted source or Web site.

"People this season need to ask themselves: is it really you?" said Robert Pregnell, senior manager for Symantec's technical product management.

"Using an infected instant messaging program to send enticing messages to everyone in the address book is a way the 'attackers' message will appear to be from a 'trusted' source," he warned.

If an e-mail or instant messaging program has been compromised, the threat will most often materialize in a way that it appears to have come from a known contact.

Attackers are also compromising the home pages of popular Web sites, allowing them to inject malicious code onto any system that visits the Web site which isn't adequately protected.

So-called free 'license' agreements required to watch, for example, a video on a social networking site, is another method of duping users into exposing their systems.

The license is not a license at all, more likely it is a piece of malicious code.

According to Symantec, Australia ranks 6th in the list of the top 10 countries originating spam across Asia-Pacific and Japan, and the number of malicious code samples (viruses, bots, Trojans, worms) has almost doubled in the last six months.

"This particularly, even outside of the festive season, is an enormous increase over previous trends, and represents the most substantial growth ever seen before in any six month period," Pregnell said.

Attackers will take advantage of any means at their disposal over the Christmas season of increased online activity.

"Shoppers read email, they browse for products, they buy and pay for products, they converse with friends to say 'Merry Xmas' using IM, they send virtual Christmas cards, share Christmas photos etc," Pregnell said.

He warned that attackers are lurking in all of the corridors which consumers are using to conduct these activities, and will use Christmas related themes to dupe victims into exposing themselves to malicious activity.

"Spam and IM threats particularly are expected to rise over the Christmas period, taking advantage of the growing numbers of virtual interactions in the community."

Pregnell said that the kind of 'social engineering' tactics that mislead victims into thinking they are doing something valid or interacting with a trusted site are increasing at an alarming rate.

For more enterprise computing news, visit For more gaming news, visit GamePro. http://www.gamepro.com/ Story copyright GamePro Media."http://www.computerworld.com/">Computerworld. Story copyright Computerworld, Inc.