Posts Tagged: CAPTCHA


3
Nov 14

Thieves Cash Out Rewards, Points Accounts

A number of readers have complained recently about having their Hilton Honors loyalty accounts emptied by cybercrooks. This type of fraud often catches consumers off-guard, but the truth is that the recent spike in fraud against Hilton Honors members is part of a larger trend that’s been worsening for years as more companies offer rewards programs.

HHONORSMany  companies give customers the ability to earn “loyalty” or “award” points and miles that can be used to book travel, buy goods and services online, or redeemed for cash. Unfortunately, the online accounts used to manage these reward programs tend to be less secured by both consumers and the companies that operate them, and increasingly cyber thieves are swooping in to take advantage.

Brendan Brothers, a frequent traveler from St. John’s in Newfoundland, Canada, discovered a few days ago that his Hilton Honors account had been relieved of more than a quarter-million points, rewards that he’d accumulated using a credit card associated with the account. Brothers said the fraudsters were brazen in their theft, using his account to redeem a half-dozen hotel stays in the last week of September, booking rooms all along the East Coast of the United States, from Atlanta, GA to Charlotte, N.C. all the way up to Stamford, CT.

The thieves reserved rooms at more affordable Hilton properties, probably to make the points stretch further, Brothers said. When they exhausted his points, they used the corporate credit card that was already associated with the account to purchase additional points.

“They got into the account and of course the first thing they did was change my primary and secondary email accounts, so that neither me nor my travel agent were getting notifications about new travel bookings,” said Brothers, co-founder of Verafin, a Canadian software security firm that focuses on anti-money laundering and fraud detection.

Brothers said he plans to dispute the credit card charges, but he’s unsure what will happen with his purloined points; nearly a week after he complained to Hilton about the fraud, Brothers has yet to receive a response from the company. Hilton also did not respond to requests for comment from KrebsOnSecurity.

PUT A PIN IN IT

Hilton gives users two ways to log into accounts: With a user name and password, or a member number and a 4-digit PIN. What could go wrong here?  Judging from changes that Hilton made recently to its login process, thieves have been breaking into Hilton Honors accounts using the latter method. According to the travel loyalty Web site LoyaltyLobby, Hilton recently added a CAPTCHA to its login process, ostensibly to make it more difficult for crooks to use brute-forcing programs (or botnets) to automate the guessing of PINs associated with member accounts.

In a post on October 30, LoyaltyLobby’s John Ollila wrote about a hacker selling Hilton Honors accounts for a tiny fraction of the real world value of points in those accounts. For example, the points stolen from Brothers would have fetched around USD $12 — even though the thieves in his case managed to redeem the stolen miles for approximately USD $1,200 worth of hotel reservations.

I did a bit of sleuthing on my own and was able to find plenty of sellers on shady forums offering them for about three to five percent of their actual value. As this ad from the online black market/drug bazaar known as Evolution Market indicates, the points can be redeemed for gift cards (as good as cash) at points.com and other locations that convert points to currency. The points also can be used to buy items from the Hilton shopping mall, including golf clubs, watches, Apple products and other electronics.

A merchant on the Evolution black market hawking hijacked Hilton points for a fraction of their value.

A merchant on the Evolution black market hawking hijacked Hilton points for a fraction of their value.

“I don’t recommend using them for personal hotel stays, but they ARE safer (and cheaper) than using a carded hotel service,” the Evolution seller advises, referring to the risks associated with using purloined points versus trying to book a stay somewhere using a stolen credit card. Continue reading →


6
Sep 14

Dread Pirate Sunk By Leaky CAPTCHA

Ever since October 2013, when the FBI took down the online black market and drug bazaar known as the Silk Road, privacy activists and security experts have traded conspiracy theories about how the U.S. government managed to discover the geographic location of the Silk Road Web servers. Those systems were supposed to be obscured behind the anonymity service Tor, but as court documents released Friday explain, that wasn’t entirely true: Turns out, the login page for the Silk Road employed an anti-abuse CAPTCHA service that pulled content from the open Internet, thus leaking the site’s true location.

leakyshipTor helps users disguise their identity by bouncing their traffic between different Tor servers, and by encrypting that traffic at every hop along the way. The Silk Road, like many sites that host illicit activity, relied on a feature of Tor known as “hidden services.” This feature allows anyone to offer a Web server without revealing the true Internet address to the site’s users.

That is, if you do it correctly, which involves making sure you aren’t mixing content from the regular open Internet into the fabric of a site protected by Tor. But according to federal investigators,  Ross W. Ulbricht — a.k.a. the “Dread Pirate Roberts,” the 30-year-old arrested last year and charged with running the Silk Road — made this exact mistake. Continue reading →


14
Oct 13

Thousands of Sites Hacked Via vBulletin Hole

Attackers appear to have compromised tens of thousands of Web sites using a security weakness in sites powered by the forum software vBulletin, security experts warn.

Attack tool for exploiting vulnerable vBulletin forums.

Attack tool for exploiting vulnerable vBulletin forums.

In a blog post in late August, vBulletin maker Jelsoft Internet Brands Inc. warned users that failing to remove the “/install” and “/core/install” directories on sites running 4.x and 5.x versions of the forum software could render them easily hackable. But apparently many vBulletin-based sites didn’t get that memo: According to Web site security firm Imperva, more than 35,000 sites were recently hacked via this vulnerability.

The security weakness lets attackers quickly discover which forums are vulnerable, and then use automated, open-source exploit tools to add administrator accounts to vulnerable sites.

Imperva said the compromised sites appear to have been hacked by one of two sets of exploit tools that have been released publicly online. The first was apparently used in a mass Website defacement campaign. A Google search for forums with the the rather conspicuously-named administrator account added in that attack (“Th3H4ck”) shows that many of the hack sites also are hosting malware. Among the sites apparently compromised is a support forum for the National Runaway Safeline and a site selling vBulletin add-ons.

The second tool does effectively the same thing, except with a bit more stealth: The administrator account that gets added to hacked forums is more innocuously named “supportvb”. Here’s a Google search that offers a rough idea of the forums compromised with this exploit, which was apparently authored or at least publicly released by this guy.

Continue reading →


14
Aug 13

Buying Battles in the War on Twitter Spam

The success of social networking community Twitter has given rise to an entire shadow economy that peddles dummy Twitter accounts by the thousands, primarily to spammers, scammers and malware purveyors. But new research on identifying bogus accounts has helped Twitter to drastically deplete the stockpile of existing accounts for sale, and holds the promise of driving up costs for both vendors of these shady services and their customers.

Image: Twitterbot.info

Image: Twitterbot.info

Twitter prohibits the sale and auto-creation of accounts, and the company routinely suspends accounts created in violation of that policy. But according to researchers from George Mason University, the International Computer Science Institute and the University of California, Berkeley, Twitter traditionally has done so only after these fraudulent accounts have been used to spam and attack legitimate Twitter users.

Seeking more reliable methods of detecting auto-created accounts before they can be used for abuse, the researchers approached Twitter last year for the company’s blessing to purchase credentials from a variety of Twitter account merchants. Permission granted, the researchers spent more than $5,000 over ten months buying accounts from at least 27 different underground sellers.

In a report to be presented at the USENIX security conference in Washington, D.C. today, the research team details its experience in purchasing more than 121,000 fraudulent Twitter accounts of varying age and quality, at prices ranging from $10 to $200 per one thousand accounts.

The research team quickly discovered that nearly all fraudulent Twitter account merchants employ a range of countermeasures to evade the technical hurdles that Twitter erects to stymie the automated creation of new accounts.

“Our findings show that merchants thoroughly understand Twitter’s existing defenses against automated registration, and as a result can generate thousands of accounts with little disruption in availability or instability in pricing,” the paper reads. “We determine that merchants can provide thousands of accounts within 24 hours at a price of $0.02 – $0.10 per account.”

SPENDING MONEY TO MAKE MONEY

For example, to fulfill orders for fraudulent Twitter accounts, merchants typically pay third-party services to help solve those squiggly-letter CAPTCHA challenges. I’ve written here and here about these virtual sweatshops, which rely on low-paid workers in China, India and Eastern Europe who earn pennies per hour deciphering the puzzles.

topemailThe Twitter account sellers also must verify new accounts with unique email addresses, and they tend to rely on services that sell cheap, auto-created inboxes at HotmailYahoo and Mail.ru, the researchers found. “The failure of email confirmation as a barrier directly stems from pervasive account abuse tied to web mail providers,” the team wrote. “60 percent of the accounts were created with Hotmail, followed by yahoo.com and mail.ru.”

Bulk-created accounts at these Webmail providers are among the cheapest of the free email providers, probably because they lack additional account creation verification mechanisms required by competitors like Google, which relies on phone verification. Compare the prices at this bulk email merchant: 1,000 Yahoo accounts can be had for $10 (1 cent per account), and the same number Hotmail accounts go for $12. In contrast, it costs $200 to buy 1,000 Gmail accounts.

topcountriesFinally, the researchers discovered that Twitter account merchants very often spread their new account registrations across thousands of Internet addresses to avoid Twitter’s IP address blacklisting and throttling. They concluded that some of the larger account sellers have access to large botnets of hacked PCs that can be used as proxies during the registration process.

“Our analysis leads us to believe that account merchants either own or rent access to thousands of compromised hosts to evade IP defenses,” the researchers wrote.

Damon McCoy, an assistant professor of computer science at GMU and one of the authors of the study, said the top sources of the proxy IP addresses were computers in developing countries like India, Ukraine, Thailand, Mexico and Vietnam.  “These are countries where the price to buy installs [installations of malware that turns PCs into bots] is relatively low,” McCoy said.

Continue reading →


9
Jan 12

Virtual Sweatshops Defeat Bot-or-Not Tests

Jobs in the hi-tech sector can be hard to find, but employers in one corner of the industry are creating hundreds of full-time positions, offering workers on-the-job training and the freedom to work from home. The catch? Employees will likely toil for cybercrooks, and their weekly paychecks may barely cover the cost of a McDonald’s Happy Meal.

Kolotibablo.com home page

The abundance of these low-skilled, low-paying jobs is coming from firms that specialize in the shadowy market of mass-solving CAPTCHAs, those blurry and squiggly words that some websites force you to retype. One big player in this industry is KolotiBablo.com, a service that appeals to spammers and exploits low cost labor in China, India, Pakistan, and Vietnam.

KolotiBablo, which means “earn money” in transliterated Russian, helps clients automate the solving of puzzles designed to prevent automated activity by bots, such as leaving spammy comments or mass-registering accounts at Webmail providers and social networking sites. The service offers an application programming interface (API) that allows clients to feed kolotibablo.com CAPTCHAs served in real time by various sites, which are then solved by KolotiBablo workers and fed back to the client’s system.

Paying clients interface with the service at antigate.com, a site hosted on the same server as kolotibablo.com. Antigate charges clients 70 cents to $1 for each batch of 1,000 CAPTCHAs solved, with the price influenced heavily by volume. KolotiBablo says employees can expect to earn between $0.35 to $1 for every thousand CAPTCHAs they solve.

The twin operations say they do not condone the use of their services to promote spam, or “all those related things that generate butthurt for the ‘big guys,'” mostly likely a reference to big free Webmail providers like Google and Microsoft. Still, both services can be found heavily advertised and recommended in several underground forums that cater to spammers and scam artists.

Registered antigate.com users can read more about why customers typically purchase the service, and how KolotiBablo is run. From the description:

“All CAPTCHAs in our service are completely solved by real humans, there are usually 500-1000 (and growing) workers online from all the world. That’s why we can process any CAPTCHAs at any volume for a fixed price $1 per 1000 CAPTCHAs.

You may probably think that using human resource inappropriate or inhumane. However, keep in mind that we pay the most of collected money to our workers who sit in the poorest corners of our planet and this work gives them a stable ability to buy food, clothes for themselves and their families. Most of our staff is from China, India, Pakistan and Vietnam.”

Continue reading →


19
Sep 11

Cultural CAPTCHAs

CAPTCHAs, those squiggly and frustrating puzzles that many Web sites require users to solve before registering or leaving comments, are designed to block automated activity and deter spammers. But for some Russian-language forums that cater to spammers and other miscreants, CAPTCHAs may also be part of a vetting process designed to frustrate foreigners and outsiders.

I'm still slogging through Disc 2 of this lengthy Soviet-era spy series.

“Verified,” one of the longest-running Russian-language forums dedicated to Internet scammers of all stripes, uses various methods to check that users aren’t just casual lurkers or law enforcement. It recently began using CAPTCHAs that quiz users about random bits of Russian culture when they register or log in.

Consider this CAPTCHA, from Verified: “Введите пропущенное число ‘… мгнoвeний вeсны.'” That translates to, “Enter the missing number ‘__ moments of spring.'”

But it may not be so simple to decipher “мгнoвeний вeсны,” the “moments of spring” bit. One use of cultural CAPTCHA is to frustrate non-native speakers who are trying to browse forums using tools like Google translate. For example, Google translates мгнoвeний вeсны to the transliteration “mgnoveny vesny.” The answer to this CAPTCHA is “17,” as in Seventeen Moments of Spring, a 1973 Russian television mini-series that was enormously popular during the Soviet Union era, but which is probably unknown to most Westerners.

Continue reading →