FRAMINGHAM – Improved network security is forcing hackers to mask virtually every Web browser exploit in a bid to evade detection, says IBM’s Internet Security Systems’.X-Force research team.
By the end of last year, according to team director Kris Lamb, nearly 100 per cent of all Web exploits were either self-encrypted or relied on obfuscation techniques to make it difficult for standard intrusion detection and intrusion prevention technologies to identify the attack code.
“In 2006, we saw about 50 per cent of Web exploits obfuscated or encoded,” Lamb said Tuesday, adding that, on average, 80 per cent were camouflaged throughout 2007. “But that jumped to almost 100 per cent by the end of the year.”
The reason for the cover-up boost is straightforward, said Lamb. “They’re not dumb. They only do what they’re forced to do,” he explained. “For them to continue to get a high rate of return, they had to understand the protection technologies that were being used. And [security] vendors were doing a pretty good job.
“A lot of network security technologies were doing a good job in 2006, when they shifted from e-mail to Web browser as an [exploit] entry point. Vendors have been keeping up with that trend and building new types of [security] technologies to keep up with technologies extending the browser, like Flash and JavaScript,” Lamb continued.
That pressured attackers into hiding more of their browser exploits, and doing a better job of concealing their work — largely by focusing on JavaScript. “More than any other technology, JavaScript is used to obfuscate and self-encrypt,” Lamb said.
JavaScript is ubiquitous — it is cross-platform and cross-browser — and its inherent complexity lends it perfectly to hacker use, argued Lamb. “Attackers can do very advantageous things, like encode it so when it goes over the wire, all the recipient sees is a data blob,” he noted.
And getting rid of JavaScript is not an option for most users. “Even I’d be hard-pressed to disable JavaScript entirely,” acknowledged Lamb. “So much of my experience and my productivity experience depends on JavaScript, or another scripting language, like VBScript or Adobescript.”
This year, he predicted, the camouflaging will continue, with hackers increasingly adding secondary scripting languages to their obfuscation and encryption portfolios. “They’ll start using other browsing scripting frameworks more — more vendor-tied scripts, like Adobescript,” Lamb said. Also known as JavaScript for Acrobat, Adobescript allows customizing of PDF files using scripting.
Hackers have already put Adobescript to work — very recently, in fact. Monday, McAfee Inc.’s Vinoo Thomas was one of several researchers who noted that attacks are under way that use at least one of the still-unnumbered vulnerabilities in Adobe Reader disclosed last week. Thomas, however, pegged the exploit to Adobe JavaScript.
“The current vulnerability can be embedded in a PDF file and manipulated through Adobe JavaScript,” he said in a warning posted to the Avert Labs’ blog on Monday.
The masking and encryption, however, is just one facet of the ongoing trend toward attacks aimed first and foremost at browsers, said Lamb. “Whether through drive-by downloads or compromising legitimate sites, or a combination of advanced, targeted phishing, the browser is involved in some way,” he said. “It’s the main frontier of exploit right now.
“We used to call the operating system the ‘keys of the castle,’ but as exploits moved up the application stack and as the browser became the new OS, it’s now the keys to castle,” he added.
