Spammers use hosted services to send unwanted mail
In an attempt to evade filters, spammers are once again changing their tactics. If last year was the year of using attachments to get past defenses, this year the junk mailers are turning to services such as Google Docs and Calendar and Microsoft SkyDrive, according to the MessageLabs Intelligence Report for May.
Last month, researchers at MessageLabs, an email security firm, began noticing an uptick in the delivery of emails that contained links to Google Docs. In addition, spammers are also leveraging Google Calendar to send what recipients believe to be an invite, but actually contains a message that, for example, hawks fake Rolex watches.
While the brunt of unwanted mail is still being delivered by botnets, a growing amount is being spread by legitimate email accounts, Mark Sunner, chief security analyst at MessageLabs, told SCMagazineUS.com.
"Getting ahold of a web mail account is highly prized in the spam community because they're whitelisted," said Sunner, who explained that often spammers acquire thousands of accounts at a time by breaking the CAPTCHA function, used to deter mass mailers.
"Obviously Google's reputation is a very trusted environment so it's going to be whitelisted," he said. So you've got a much higher chance of going through if it's emanating from a Google address pointing to a Google document, than if it were coming from a bot. The second [benefit] is bandwidth...You've got a high availability hosting environment."
The MessageLabs report also highlighted a new phishing trend in which criminals are promising environmental benefits for bank customers -- such as eliminating paper statements -- in exchange for providing their credentials.