China's Spam Surge
In its report issued Monday, Symantec noted a sharp spike in spam messages containing URLs that use ".cn" or the top level domain (TLD) for China. During the month of July, the amount of spam rose from virtually zero to around 450 spam domains.
One reason for the growing popularity of Chinese domains was the ban on TLDs from other countries due to spam blacklists, Symantec offered. Spammers are thus forced to register new TLDs from countries not yet on the blacklists.
Spam is also becoming increasingly localized for specific target markets, said Symantec.
The security vendor also noted a drop in spam using Hong Kong (".hk") TLDs, which could be a result of the recent enactment of anti-spam laws in the country.
Symantec's report also noted a decline in image spam, where some 10 percent of all spam messages in July were image-based, compared to about 50 percent earlier this year.
However, the decline in image spam is giving rise to attachments in other forms as the choice of spammers. Greeting card spam topped the list.
Over 250 million greeting card spam messages were targeted, each containing links to trojans which get downloaded when clicked.
Other forms of spam on the rise include PDF spam, Excel and Zip file spam. Although Excel and Zip files remain low, Symantec's report stated that finding new attachment formats is an indication of "just how committed spammers are to evading antispam filters".