Increased use of stealth techniques such as rootkits is leading to fewer reports of new viruses, according to a study by net security outfit VeriSign iDefense.
Since 2003, VeriSign iDefense has been collecting and recording information on every uniquely identifiable malicious code, using public and private resources. Discovery of malicious codes was steadily growing between 2003 and 2005, but from January to June 2006 VeriSign iDefense noticed a significant downward trend each month.
Its conclusions are markedly different from those of anti-virus vendors, who report a decrease in mass-mailing worms but an increase in more targeted attacks.
VeriSign iDefense has a number of theories about why it is seeing fewer examples of malware doing the rounds. For one, anti-virus programs may be improperly detecting polymorphic codes as older variants or code families. Then again, malware authors might be turning to phishing and pharming attacks as a means to rack in illicit funds. As such attacks grow in popularity, the theory goes, they might start to replace malicious codes as a means to gain personal information for financial gain.
While it's true that phishing attacks are gaining in sophistication, VeriSign iDefense neglects to mention that key-logging Trojans are one of the most effective means to gain secret account information.
However, the company believes the most significant factor in the decrease of malware it reports is the increased use of rootkit techniques. Rootkits, designed to push malware "under the radar", are increasingly foiling anti-virus programs and other security techniques, it says.
VeriSign iDefense reckons the number of malicious codes installed today is still significant, but simply not being detected.
Senior malicious code analyst Frederick Doyle said: "Levels of spamming continue to be a good indicator of malicious code use, as those techniques are generally used by the same types of hackers. As the public improves in its defences against spamming, malicious code users are increasingly turning to different means of attack." ®