More than two in three exploits kits that attempt to inject malware into web surfers' computers were developed in Russia - and at least one in two exploit rather old vulnerabilities.

Blackhole 2.0 is the most often used hacking toolkit - installed on websites to attack and take over visitors' computers - but it targets fewer software security holes than rival cybercrime kits. That's according to a fresh report by managed security biz Solutionary.

Contrary to hype that exploit kits target unpatched flaws in products, Solutionary found the majority (58 per cent) of exploited vulnerabilities were more than two years old.

The company reviewed 26 commonly used kits and discovered code abusing security bugs dating as far back as 2004, evidence that old vulnerabilities continue to be mined for profit for cybercrooks. Criminal hackers typically compromise otherwise legitimate websites to plant hacking toolkits and distribute fake antivirus software, banking Trojans and other nasties.

Researchers at the security firm concluded that antivirus products cannot detect 67 per cent of malware being distributed, a finding that is likely to be controversial. The practical upshot is that surfers would be wise to regularly update applications - especially Adobe Flash, web browsers and the Java runtime - rather than rely on security scanners to block any attacks that come their way.

"Exploit kits largely focus on targeting end-user applications,” said Rob Kraus, a director of security research at Solutionary. “As a result, it is vital that organisations pay close attention to patch management and endpoint security controls in order to significantly decrease the likelihood of compromise."

A complete copy of Solutionary's Q4 2012 threat report can be found here (registration required). ®