The increase, says the IT security vendor, shows that cybercriminals are adopting a variety of new and more sophisticated techniques, such as spoofing smart printers/scanners.
According to the report, the spam level in the UK was 75.5% in September, with one in 129.9 emails being blocked as malicious. The UK remained the second most targeted country, with one in 221.1 emails identified as phishing attacks.
Commenting on the September statistics, Paul Wood, a senior intelligence analyst with Symantec, said that the unprecedented high-water mark with polymorphic malware underlines the nature by which cyber criminals have escalated their assault on businesses in 2011, fully exploiting the weaknesses of more traditional security countermeasures.
Further analysis, he says, also reveals that the social engineering behind many of these attacks became even more sophisticated with cyber criminals adopting a variety of new techniques such as spoofing a smart printer/scanner.
Some of the newest printers have a feature that allows users to email scanned documents to a specified email address on demand. Malware authors are now using social engineering tactics that simulate this feature to send executables in a compressed “.zip” archive via email, disguising the attachment as a scanned document.
Wood adds that the idea of your office printer sending you malware is perhaps an unlikely one, but perhaps this false sense of security is all that is required for such an attack to succeed.
The Symantec analyst went on to say that JavaScript has also been spotted as a means of infection by hackers during the month he notes that, for spammers, hosting simple JavaScript obfuscation pages on free hosting sites can increase the lifetime of that site before the site operator realizes the page is being used for malicious activity.
“JavaScript is popularly used for redirecting visitors of a compromised Web site to the spammers landing page. While some of these techniques have been common in malware distribution for some time, spammers are increasingly using them”, he explained.