Tag Archive for AOL

CAPTCHAs Broken

CAPTCHAs BrokenMims Bits on MIT‘s Technology Review reports that researchers at UC San Diego have figured out how spammers use low-cost workers in Russia, Southeast Asia, and China to solve millions of CAPTCHAs in near real-time. A CAPTCHA is that bit of distorted text you have to type back at a webpage when you’re trying to sign up for a new email account or leave a blog comment.

CAPTCHAIn order to prevent spammers from flooding the web with their malware researchers developed CAPTCHAs. CAPTCHAs are designed to be easy for humans to solve but challenging enough for computers to get right that automated systems would not be effective.

In what Mims calls an epic new analysis by the UC San Diego researchers, they uncovered the “seedy underbelly” of a sophisticated, highly automated, worldwide network of services that help spammers get past the CAPTCHAs. The article says that the inventors of CAPTCHA probably didn’t expect thousands of laborers working for less than $50 a month would be recruited by spammers to solve an endless stream of CAPTCHAs. Automated middlemen deliver the  CAPTCHAs to the workers and then sell the results to spammers in real-time so that their spambots can use those solutions to post to blogs and set up fraudulent email accounts according to a paper (PDF) delivered at the USENIX Security 10 Symposium.

The UC San Diego researchers analyzed where the workers involved in this scheme were located and found that they are based in India, Russia, Southeast Asia, and China. The system is so efficient at delivering CAPTCHAs to workers in these remote locales that the average time for delivery of a solution hovers around 20 seconds. ImageToText, one of the CAPTCHA services the researchers experimented with was able to deliver correct results in “a remarkable range of languages,” including Dutch, Korean, Vietnamese, Greek, and Arabic.

Klingon,Even setting the sample CAPTCHAs to Klingon, as a control in their experiment, could not stop ImageToText, according to Technology Review. The workers managed to solve a handful of the Klingon CAPTCHAs despite odds of less than one in one thousand of their randomly getting the right answer.

The results of this landmark study, says Mims, show that a number of sites, including those run by Microsoft (MSFT), AOLGoogle (GOOG), and the widely used reCAPTCHA, are regularly compromised by spammers employing these services. The researchers conclude that their investigation with an anonymous “Mr. E” who actually runs one of these services, proves that for advanced spammers, CAPTCHAs aren’t so much a barrier as a cost of doing business.

DarkReading has a report that independent security researcher Chad Houck recently demonstrated his work on solving Google’s reCAPTCHA. reCAPTCHA was designed to stop software bots attempts to create free accounts on the Google services for their malware ways.  Despite recent enhancements made by Google, DarkReading says Houck came up with algorithms that could beat reCAPTCHA 30 percent of the time.

Google logoA 30% success rate means that automated software using Mr. Houck’s algorithm will be able to create one Google account out of just three attempts. Multiply those odds by the endless attempts by tens of thousands of zombies in a typical botnet, reCAPTCHA is broken.

In the DarkReading article, Houck notes that “[ReCAPTCHA] has never been wholly secure. There are always ways to crack it.” The researcher has since published a white paper on it, and has also released his algorithms online. For now, at least, a Google spokesperson says there has not been any sign of this particular attack being actively used.

Related articles

 

Ralph Bach has been in IT long enough to know better and has blogged from his Bach Seat about IT, careers, and anything else that catches his attention since 2005. You can follow him on LinkedInFacebook, and Twitter. Email the Bach Seat here.

Microsoft Security Report

Microsoft Security ReportMicrosoft (NASDAQ MSFT) released the latest Microsoft Security Intelligence Report (SIRv8) on April 26, 2010. Data for SIRv8  came from 500 million PCs across the globe between July and December 2009 and for the first time separates enterprise user and consumer user malware trend data. The data included in the 250-page report says that enterprises and consumers each suffer from different types of malware threats.

Microsft security goog news

Microsoft logoThe good Microsoft security news from the SIR 8 report is that newer operating systems and up-to-date applications are the most secure. Windows 7 and Vista Service Pack 2 have the lowest infection rates per 1,000 executions of the Microsoft Malicious Software Removal Tool (MSRT) in the second half of last year. (pg. 85). Microsoft runs the Malicious Software Removal Tool before installing Windows updates.

Windows OSPC's cleaned/1,000 MSRT
XP SP121.7
XP SP214.5
Win 7 32-bit2.8
Vista SP2 32-bit2.2
Vista SP2 64-bit1.4
Win 7 64-bit1.4

The report shows that the more recent versions of Microsoft Windows are less vulnerable to attack. Cliff Evans, Microsoft UK’s head of security and privacy says only about 5% of the vulnerabilities are in Microsoft software. This has led to a shift in emphasis to targeting third-party programs and utilities. In XP, around 45% of attacks exploited third-party (i.e. non-Microsoft) code, with Vista and Windows 7 it’s around 75% according to an article in the Guardian.

Application attacks continue to increase. Running updated software decreases the attack surface and increases Microsoft security robustness. The report shows that attackers target Internet Explorer 6 (IE 6) up to four times more often than the newer version IE 7 (pg.33). Matt Thomlinson, general manager of product security in Microsoft’s Trustworthy Computing group told DarkReading, “With Internet Explorer, IE 6 is four times more targeted in drive-by attacks.” Thomlinson says SIR 8 provides the first real results to illustrate this.

Browser attacks

The Microsoft security report says that nearly 75% of the browser-based exploits encountered in 2H09, were third-party applications, including Adobe Reader, RealPlayer, Apple QuickTime, and AOL software (pg.26). This means Windows Update is not enough to protect users, who must also install updates from Adobe, Apple, and other software suppliers.

Attacks against Microsoft Office make use of older vulnerabilities that have mostly been fixed and can easily be avoided by keeping the software suite up to date. The majority of Office file format attacks can be avoided by applying service packs (pg. 43). For example, 75.8% of the attacks on Microsoft Office files exploited a single vulnerability (CVE-2006-2492, the Malformed Object Pointer Vulnerability in Microsoft Office Word), which was found in 2006.

The report found that enterprise users contract more worms, “In the enterprise, worms are more of a problem, which is not a surprise in that you have networks with trusted file shares and USB devices, and they are more susceptible to those transmission mechanisms,” Thomlinson told DarkReading. “This is the first time we’ve had data allowing us to separate [enterprise and consumer machines] and show differences [in malware prevalence.]” Worms were found in 32 percent of enterprise PCs.

ThreatPresent %
Worms32
Miscellaneous Trojans18
Unwanted software16
Trojan down-loaders and droppers13
Password-stealers and monitoring tools7
Backdoor programs 5
Viruses 4
Exploits 3
Adware3
Spyware1

Rogue anti-virus attacks

Windows in both the enterprise and the consumer markets were hit hard by rogue anti-virus attacks last year. Rogue security software was found on 7.8 million up 46% from 5.3 million in the second half of last year. The most detected rogue security software family, Win32/FakeXPA, was also the third-most prevalent overall threat detected by Microsoft worldwide in 2H09. Three other rouge software families were also widely detected:

  • Win32/Yektel,
  • Win32/ FakeSpypro, and
  • Win32/Winwebsec.

MSFT claims that attacks are now motivated by financial gain, with a “black economy” of malware authors, botnet herders, and other criminals working together to exploit vulnerabilities in Windows PCs. “We’re seeing that the criminals are more professional and organized,” Thomlinson says. “This is really about criminals in shirts and ties, not with tattoos.” Criminals are becoming more specialized in different aspects of cybercrime. They are then coordinating with criminals with other specialties. He says. “Threats are being packaged together and sold as commodities and kits,” he says. “It struck us as we looked at botnets that this is an early version of cloud computing: There is computing available for whatever use they have in mind, and they are taking advantage of many machines to do that. This is the ‘black cloud’ of computing.

rb-
The next report will be interesting as attackers focus their attention on Win7 as it becomes wider deployed. The takeaway from the report is:
  • Keep your installed software patched to current levels.
  • Running old versions of operating systems, browsers, and application software exposes companies to additional unnecessary risks (Ask Google).
  • Invest into initiatives that get systems upgraded to the newest technology available.

 

Ralph Bach has been in IT long enough to know better and has blogged from his Bach Seat about IT, careers, and anything else that catches his attention since 2005. You can follow him on LinkedInFacebook, and Twitter. Email the Bach Seat here.