Posts Tagged: Matthew Green

Mar 15

Microsoft Fixes Stuxnet Bug, Again

Microsoft today shipped a bundle of security updates to address more than three dozen vulnerabilities in Windows and associated software. Included in the batch is a fix for a flaw first patched in 2010 — the very same vulnerability that led to the discovery of the infamous cyberweapon known as Stuxnet. Turns out, the patch that Microsoft shipped to fix that flaw in 2010 didn’t quite do the trick, leaving Windows users dangerously exposed all this time.

brokenwindowsOn this, the third Patch Tuesday of 2015, Microsoft pushed 14 update bundles to address at least 43 separate vulnerabilities in Internet Explorer, Exchange, Office and a host of other components.

Five of the the patches released today fix flaws that Microsoft has assigned its most serious “critical” label, meaning the vulnerabilities these patches fix can be exploited to compromise vulnerable systems through little or no action on the part of the user — save for perhaps opening a booby-trapped file or visiting a hacked/malicious Web site.

One of the more curious critical fixes is MS15-020, which according to HP’s Zero Day Initiative researchers addresses the same vulnerability that Microsoft patched in August 2010. That vulnerability — first revealed in a post on this blog July 15, 2010 — was later discovered to have been one of four zero-day flaws used in Stuxnet, a weapon of unprecedented sophistication that is now widely considered to have been a joint U.S. and Israeli project aimed at delaying Iran’s nuclear ambitions. The folks at HP TippingPoint have published a blog post on their work in uncovering the failed fix, and how the original 2010 patch missed the mark. For more on Stuxnet, check out Kim Zetter‘s excellent new book, Countdown To Zero Day. Continue reading →

May 14

True Goodbye: ‘Using TrueCrypt Is Not Secure’

The anonymous developers responsible for building and maintaining the free whole-disk encryption suite TrueCrypt apparently threw in the towel this week, shuttering the TrueCrypt site and warning users that the product is no longer secure now that Microsoft has ended support for Windows XP.

tcSometime in the last 24 hours, began forwarding visitors to the program’s home page on, a Web-based source code repository. That page includes instructions for helping Windows users transition drives protected by TrueCrypt over to BitLocker, the proprietary disk encryption program that ships with every Windows version (Ultimate/Enterprise or Pro) since Vista. The page also includes this ominous warning:

“WARNING: Using TrueCrypt is not secure as it may contain unfixed security issues”

“This page exists only to help migrate existing data encrypted by TrueCrypt.”

“The development of TrueCrypt was ended in 5/2014 after Microsoft terminated support of Windows XP. Windows 8/7/Vista and later offer integrated support for encrypted disks and virtual disk images. Such integrated support is also available on other platforms (click here for more information). You should migrate any data encrypted by TrueCrypt to encrypted disks or virtual disk images supported on your platform.”

Doubters soon questioned whether the redirect was a hoax or the result of the TrueCrypt site being hacked. But a cursory review of the site’s historic hosting, WHOIS and DNS records shows no substantive changes recently.

What’s more, the last version of TrueCrypt uploaded to the site on May 27 (still available at this link) shows that the key used to sign the executable installer file is the same one that was used to sign the program back in January 2014 (hat tip to @runasand and @pyllyukko). Taken together, these two facts suggest that the message is legitimate, and that TrueCrypt is officially being retired.

That was the same conclusion reached by Matthew Green, a cryptographer and research professor at the Johns Hopkins University Information Security Institute and a longtime skeptic of TrueCrypt — which has been developed for the past 10 years by a team of anonymous coders who appear to have worked diligently to keep their identities hidden.

“I think the TrueCrypt team did this,” Green said in a phone interview. “They decided to quit and this is their signature way of doing it.”

Green last year helped spearhead dual crowdfunding efforts to raise money for a full-scale, professional security audit of the software. That effort ended up pulling in more than $70,000 (after counting the numerous Bitcoin donations) —  far exceeding the campaign’s goal and demonstrating strong interest and support from the user community. Earlier this year, security firm iSEC Partners completed the first component of the code review: an analysis of TrueCrypt’s bootloader (PDF). Continue reading →