Spammers have found a new way to circumvent spam filters and are using Google Docs to do so.

According to McAfee's spam researchers, spammers are hosting their message on legitimate sites such as Google Docs, making it harder for anti-spam technology to block the messages.
As a result, the junk mail can slide under the radar of many e-mail filters.
In the Google Docs attacks spammers send a simple text e-mail that includes a link to a document hosted on the Google service. The Google document actually includes the spammy message, for example advertising medications, stocks or other items.
The Google Docs spam is similar to image hosting spam, whereby spammers use legitimate image hosting services to serve up their message.
The volume of Google Docs spam isn't very high. On a recent day McAfee Avert Labs' spam traps captured 517 spam e-mail messages that included links to Google Docs. Internet users should be aware that a link to any Web site, including Google Docs, could be malicious.
Spam poses a significant threat to businesses and consumers. Not only does unwanted e-mail clog inboxes and take up time, cybercrooks use spam to deliver malicious software or trick unsuspecting consumers into giving up personal information through phishing attacks.