Following the dip in January by the removal of some botnet providers, spam is on the rise again in Australia, according to security experts.
A report entitled Intelligence Report 2011 from Symantec division, MessageLabs, noted that February was one of the more prolific periods for spam with one email in every 365 in the country identified as malicious, the highest figure in 12 months.
This contrasted with reports from the fourth quarter of 2010, where vendors said that spam levels fell due to the closure of some programs such as Spamit.com.
The spam rise is due to the appearance of botnets, such as Zeus, which went underground after arrests in the US and UK late last year. Zeus was designed to evade security software and grab online banking details.
In addition, the MessageLabs report suggests that malicious files have increased in frequency along with PDF files, the most popular file format for malware distribution on a global scale.
MessageLabs senior analyst, Paul Wood, said in a statement that PDF files account for a larger proportion of document file types used to carry out attacks.
“In 2009, approximately 52.6 per cent of targeted attacks used PDF exploits, compared with 65 per cent in 2010, an increase of 12.4 per cent," he said. "Based on our research, 76 per cent of targetted malware could be used for PDF-based attacks by mid-2011."
M86 Asia Pacific vice president, Jeremy Hulse, told Computerworld Australia that while mobile malware is still a bigger threat, he agrees that spam levels have increased as botnets re-emerge.
"It was quiet in December and January but the botnet providers have regrouped and built better systems," he said. "We're seeing spam come through more as a blended threat where it not only has a payload in the email, but also redirects users to legitimate Websites that have malware on it."
He added that there is the potential for Zeus and another botnet called Spyeye to combine to create complex malware. This has emerged overseas when it was discovered last month that code from Zeus and SpyEye was combined to target banks.
However, with 550,000 new pieces of mobile malware created every day, Hulse said people need to remain vigilant on smart phones as well as computers.
"I actually had a malware SMS on my mobile the other day which said I'd won $9.8 million and included a link to a fake Website," he said. "With the advent of people using tablets such as the iPad, mobile malware is just going to increase and we are seeing threats that attack the different operating systems."
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