“But we didn’t observe any prevalence of Java malware abusing these newer vulnerabilities above malware abusing the older Java vulnerabilities, CVE-2012-0507 and CVE-2012-1723. The reason behind this might be that only Java 7 installations were vulnerable to CVE-2012-4681 and CVE-2012-5076, whereas CVE-2012-0507 and CVE-2012-1723 also target Java 6,” he said.
As there are still many users that use Java 6, the malware writers might have tried to target Java 6 installations by including older vulnerabilities in the exploit package. During 2012 there were two kinds of Java vulnerabilities one applied to both multiple versions of Java including Java 6 and 7, and the others only applies to Java 7.
“So when new vulnerabilities that are only applicable to Java 7 are discovered, the attacker’s strategy was usually to combine it with older vulnerabilities that cover more versions of Java. In that way, they could achieve more coverage than just using a single exploit in one package,” Oh said.
Of the four Java vulnerabilities from 2012 only one of which was a zero day vulnerablity. The other three flaws already had patches available when the malware targeting them appeared. The warning here is to install patches as soon as they come out.