Trusteer rebuffs bank security bypass claims
Smacks down Times and researchers
Trusteer has downplayed the significance of reports that it might have been possible to bypass its anti-keylogger online banking protection technology.
Digit Security presented research at the 44Con conference last month suggesting that Trusteer's Rapport technology could be ‘switched-off’ and ‘bypassed’ using functionality provided by Rapport itself. It suggested the vulnerability arose as a result of a design flaw rather than a bug.
Trusteer's Rapport transaction security technology is offered as a voluntary download by 50 banks worldwide, including NatWest and HSBC in the UK, ING Direct USA and PayPal. The technology is designed to allow banking transactions to take place without interception even on compromised (malware-infected) machines by interfering with any attempts to log keystrokes or capture screenshots.
Digit Security said the Trusteer Rapport flaw has not been abused by existing malware. The Times followed up on the research with an article (behind paywall here) on the threat.
In a statement issued on Monday, Trusteer chief exec Mickey Boodaei said that it had corrected the flaw discovered by Digit Security. It criticised The Times and Digit Security for failing to give it enough time to design a fix.
An article published in The Times of London Money Section on October 1st 2011, describes a method to bypass Trusteer Rapport's anti-keylogging mechanism and suggests that "millions of customers are at risk of fraud because of a fundamental flaw". We investigated the claim and found it to be a speculative threat that is not currently incorporated in malware. We fixed the issue, but asked The Times for a few days to complete our testing. They decided to run the story anyway.
This situation illustrates why the information security industry has self-instituted a responsible disclosure process. Most researchers follow this practice, and do not disclose a vulnerability publicly until they have advised the software developer of the problem and given them the opportunity to fix it. This is designed to protect users. In this instance, the vulnerability code was made public without sharing it with us first, even though we made multiple requests to see it.
Trusteer downplayed the significance of the flaw discovered by Digit Security, arguing that exploiting it would be difficult in practice. The security company said that even if a hacker were able to use the flaw to disable anti-keylogging functions in Rapport, other secondary security protection technologies would still be in play.
Fortunately, the exploit code published by the researcher (http://www.digit-security.com/files/exploits/rapport-listen.c) doesn't represent a real threat for the following reasons. First, it requires the user to be an administrator, which is not the default mode on Mac computers. Second, this code triggers the operating system to ask for the user's admin password each time the code tries to read keystrokes. Finally, the code cannot be used to read password fields due to restrictions set by the system.
Even if this threat were real, our customers would not be at risk. That's because Trusteer provides a wide range of defences against fraud. It prevents malware from installing on the computer and accessing information inside the browser; it verifies the legitimacy of the website that the customer is currently using to prevent the submission of sensitive information to fraudulent websites; it detects malware activity and removes the files associated with it; and it monitors web pages loaded into the browser and removes malicious content that tries to exploit vulnerabilities in the browser or its add-ons.
Trusteer concludes by criticising Digit Security for failing to follow accepted industry practices on responsible disclosure.
Trusteer accepts feedback from all sources that follow responsible disclosure methods which allow vendors to investigate and, if necessary, provide a fix before a vulnerability is made public. This is an accepted practice in the information security industry and was created specifically to avoid placing users at risk. The researcher who collaborated with The London Times failed to follow this code of conduct. It was irresponsible, and is exactly the type of behaviour we and the industry as a whole are trying to prevent.
More on Digit Security's research can be found here. ®
Anyone use this?
I took one look and decided I'd rather have the bloody trojan.
Anything squirreling itself that far into the guts of the OS is asking for trouble come patch time IMHO. Also appears to lack that all important "load on request only" option, so that for the 99.99% of the time I'm *not* talking to a bank it's not loaded, not chewing resource in the background and not providing yet another reason for things to go titsup unexpectedly.
Worst part was that the bank punting this said I didn't have to have it, but once it had been seen in use once they'd never allow another connection without it. At least you can remove malware.....
get on the phone to The Times and ask them why they were so irresponsible in running the story without giving Trusteer a reasonable amount of time to plug the hole
One the one hand, he complains that the exploit code was released, and on the other admits that the code which was actually released was useless as actual malware and was really just a proof of concept... Make your mind up?
The same attack targeting windows was also demonstrated at 44con, but code was not released for this specifically because it would have been useful for incorporating into malware.
Despite their claims to the contrary, rapport is basically just another AV product, but with a more limited scope in that it specifically targets a particular kind of malware. It cannot prevent 0day attacks, all it does is change the target parameters slightly. Think of it like Windows 7, when it was new malware couldn't cope with it, but as it becomes more widespread malware authors simply need to update their code.
The presentation at 44con talks specifically about the "anti keylogger protection" provided by rapport, it doesn't go into anything else.
The purpose of the anti keylogger protection is to prevent a keylogger from capturing your keystrokes even if one has gotten installed, and it works by capturing keystrokes at a low level, obfuscating them and then deobfuscating them by way of a browser plugin before sending it to the remote site. The intention is that given the location where known keyloggers hook into the system they will receive the obfuscated keystrokes instead of the real ones. This only works however, providing keyloggers continue playing by the same rules. What if keyloggers attempt to capture the keystrokes *before* rapport gets them, or similarly since rapport clearly has the capability to deobfuscate the keystrokes, what if the malware simply uses the same approach (as is the case in the proof of concept code linked in the article).
Sure, the keylogger protection breaks the method existing known keyloggers use, but it doesn't stop keyloggers it just forces keylogger authors to take a new approach, and you can guarantee that the more widespread rapport becomes and the more banks that push it onto their customers sooner or later malware authors will adapt, just as they have already adapted to different os versions, different browsers, different av products etc.