Cybercrooks have begun distributing an item of malware that poses as a Java security update.
Oracle released a new version of Java 7 (Java 7u11) on Sunday (13 January) to addresses zero-day vulnerability that has been exploited in the wild. The update was important because the underlying exploit had been "weaponised" and bundled in widely available black market exploit kits in the week prior to Oracle's security update.
The security flap generated plenty of attention, especially after US CERT warned that despite the update it remained a bad idea to run Java plugins in browsers.
Cybercrooks have latched onto this publicity by pushing out a fake Java security update, net security firm Trend Micro warns. The fake updater actually opens a backdoor onto Windows systems, providing users download and apply it.
"Though the dropped malware does not exploit CVE-2012-3174 or any Java-related vulnerability, the bad guys behind this threat is clearly piggybacking on the Java zero-day incident and users' fears," said Paul Pajares, fraud analyst at Trend Micro in a blog post. "The use of fake software updates is an old social engineering tactic."
Trend advises users to obtain their Java security updates directly from Oracle rather than from third-party websites.
Earlier this week ads for a Java exploit that supposedly attacks a brand-new vulnerability were offered for sale through an underground hacking forum at $5,000 a pop. The ad has since been pulled. Although the claim from cybercrooks that they have discovered yet another unpatched Java security hole remains unsubstantiated, the potential threat is all too credible.
Metasploit founder HD Moore reckons that Oracle is sitting on a backlog of Java flaws that will take up to two years to patch, even without the appearance of further problems.
"The 'two-year' comment was based on the types of problems that have been found in Java over the last 12 months, namely sandbox escapes [achieved] by abusing reflection APIs," Moore explained in an email to El Reg. "These types of flaws are difficult to find and sometimes even harder to fix. Oracle has already spent a year working through these issues based on the initial Security Explorations report, but will likely need another two years to fix them completely."
Separately Trend Micro warned earlier this week that the latest Java security update may be incomplete. The update attempts to address two security bugs but fails to quash one of these completely.
The security firm advises users to avoid Java where possible, particularly as a plugin to their browsers, where the main danger arises. Users obliged to use Java, perhaps on the small percentage of sites which require it or for work-related reasons, can minimise their exposure by disabling Java on their main day-to-day browser and using a secondary browser with an enabled Java plugin solely for those sites. This tactic for minimising exposure to Java-based attacks is advocated by many security firms. ®