Portable Document Formats, commonly know as PDFs, are becoming a popular decoy that spammers are using within image spam, according to a recent report by BorderWare Technologies.
The report found that more than 30 image spam campaigns are being run every day with more than 50 percent of these being PDF-based. The BorderWare Security Network Portal tracks domain reputation in real time and gathers data from more than 8,000 customer systems in 65 countries. Despite the decrease in image spam, PDF spam rose.
“Image spam was only the first wave of how spammers are trying to beat current technologies,” said Tim Leisman, CEO of BorderWare Technologies.
This finding comes a week after Commtouch noted similar ones in, “Email Threats Trend Report for the second quarter of 2007.”
It found that PDF spam rose at the end of the second quarter and during one massive attack, PDF spam comprised 10 percent to 15 percent of spam. Meanwhile, image spam dropped to 15 percent of spam, down from 30 percent in the first quarter of 2007.
It also noted that spam and viruses are using the same botnets to distribute both types of e-mail-borne threats, sometimes even in the same e-mail message. Botnets are a collection of software robots, or bots, which run autonomously usually for unscrupulous purposes.
