Posts Tagged: twitter


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.

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22
May 13

Krebs, KrebsOnSecurity, As Malware Memes

Hardly a week goes by when I don’t hear from some malware researcher or reader who’s discovered what appears to be a new sample of malicious software or nasty link that invokes this author’s name or the name of this blog. I’ve compiled this post to document a few of these examples, some of which are quite funny.

loginbetabot1

Source: Exposedbotnets.com

Take, for example, the login panel for “Betabot“: Attempt to log in to this malware control panel with credentials that don’t work and you’ll be greeted with a picture of this author, accompanied by the following warning: “Enter the correct password or I will write a 3-part article on this failed login attempt.”

The coders behind Betabot evidently have several versions of this login panel warning: According to a threat intelligence report being released tomorrow by RSA, the latest iteration of this kit uses the mugshot from my accounts at Twtter (follow me!) and Facebook (like it!).

As first detailed by Sophos’s award-winning Naked Security blog, the code inside recent versions of the Redkit exploit kit includes what appears to be a message blaming me for…well, something. The message reads: “Crebs, its [sic] your fault.”

sophosredkit

Text string inside of the Redkit exploit kit. Source: Sophos

The one I probably hear about most from researchers is a text string that is built into Citadel (PDF), an offshoot of the ZeuS banking trojan botnet kit that includes the following reference: “Coded by BRIAN KREBS for personal use only. I love my job and my wife.”

A text string inside of the Citadel trojan. Source: AhnLab

A text string within the code of the Citadel trojan. Source: AhnLab

Those are just the most visible examples. More commonly, if Yours Truly is invoked in the name of cybercrime, it tends to show up in malicious links that lead to malware. Here are a few just from the past couple of weeks:

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20
Feb 13

Critical Security Updates for Adobe Reader, Java

Adobe and Oracle each released updates to fix critical security holes in their software. Adobe’s patch plugs two zero-day holes that hackers have been using to break into computers via Adobe Reader and Acrobat. Separately, Oracle issued updates to correct at least five security issues with Java.

javaiconThe Java update comes amid revelations by Apple, Facebook and Twitter that employees at these organizations were hacked using exploits that attacked Java vulnerabilities on Mac and Windows machines. According to Bloomberg News, at least 40 companies were targeted in malware attacks linked to an Eastern European gang of hackers that has been trying to steal corporate secrets.

Oracle’s update brings Java on Windows systems to Java SE 7 Update 15, and Java 6 Update 41. Most consumers can get by without Java installed, or least not plugged into the browser. Because of the prevalence of threats targeting Java installations, I’d urge these users to remove Java or unplug it from the browser. If this is too much trouble, consider adopting a dual-browser approach, keeping Java unplugged from your main browser, and plugged in to a secondary browser that you only use to visit sites that require the plugin. To find out if you have Java installed, visit java.com and click the “Do I have Java?” link below the big red button. Existing users can update Java from the Java Control Panel, clicking the Update tab and then the “Update Now” button.

Apple has issued an update that brings Java up-to-date on security patches but also disables the Java plugin from Web browsers on the system. Apple also issued a malware removal tool that it said should remove from Macs the most common variants of malware that used the most recent Java exploits. Continue reading →


27
Nov 12

All Banks Should Display A Warning Like This

One of my Twitter account followers whose tweets I also follow  — @spacerog – shared with me the following image, which he recently snapped with his phone while waiting in line at the Philadelphia Federal Credit Union. It’s an excellent public awareness campaign, and one that I’d like to see replicated at bank branches throughout the country.

An anti-fraud awareness campaign by the PFCU.


21
Jun 12

A Closer Look: Email-Based Malware Attacks

Nearly every time I write about a small- to mid-sized business that has lost hundreds of thousands of dollars after falling victim to a malicious software attack, readers want to know how the perpetrators broke through the victim organization’s defenses, and which type of malware paved the way. Normally, victim companies don’t know or disclose that information, so to get a better idea, I’ve put together a profile of the top email-based malware attacks for each day over the past month.

Top malware email attacks in past 30 days. Source: UAB

This data draws from daily reports compiled by the computer forensics and security management students at the University of Alabama at Birmingham, a school I visited last week to give a guest lecture and to gather reporting for a bigger project I’m chasing. The UAB reports track the top email-based threats from each day, and include information about the spoofed brand or lure, the method of delivering the malware, and links to Virustotal.com, which show the percentage of antivirus products that detected the malware as hostile.

As the chart I compiled above indicates, attackers are switching the lure or spoofed brand quite often, but popular choices include Amazon.com, the Better Business Bureau, DHL, Facebook, LinkedIn, PayPal, Twitter and Verizon Wireless.

Also noticeable is the lack of antivirus detection on most of these password stealing and remote control Trojans. The average detection rate for these samples was 24.47 percent, while the median detection rate was just 19 percent. This means that if you click a malicious link or open an attachment in one of these emails, there is less than a one-in-five chance your antivirus software will detect it as bad.

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17
May 12

Facebook Takes Aim at Cross-Browser ‘LilyJade’ Worm

Facebook is attempting to nip in the bud a new social networking worm that spreads via an application built to run seamlessly as a plugin across multiple browsers and operating systems. In an odd twist, the author of the program is doing little to hide his identity, and claims that his “users” actually gain a security benefit from installing the software.

At issue is a program that the author calls “LilyJade,” a browser plugin that uses Crossrider, an emerging programming framework designed to simplify the process of writing plugins that will run on Google ChromeInternet Explorer, and Mozilla Firefox.  The plugin spreads by posting a link to a video on a user’s Facebook wall, and friends who follow the link are told they need to accept the installation of the plugin in order to view the video. Users who install LilyJade will have their accounts modified to periodically post links that help pimp the program.

The goal of LilyJade is to substitute code that specifies who should get paid when users click on ads that run on top Internet properties, such as Facebook.com, Yahoo.com, Youtube.com, Bing.com, Google.com and MSN.com. In short, the plugin allows customers to swap in their own ads on virtually any site that users visit.

I first read about LilyJade in an analysis published earlier this month by Russian security firm Kaspersky Labs, and quickly recognized the background from the screenshot included in that writeup as belonging to user from hackforums.net. This is a relatively open online hacking community that is often derided by more elite and established underground forums because it has more than its share of adolescent, novice hackers (a.k.a. “script kiddies”) who are eager to break onto the scene, impress peers, and make money.

It turns out that the Hackforums user who is selling this plugin is doing so openly using his real name. Phoenix, Ariz. based hacker Dru Mundorff sells the LilyJade plugin for $1,000 to fellow Hackforums members. Mundorff, 29, says he isn’t worried about the legalities of his offering; he’s even had his attorney sign off on the terms of service that each user is required to agree to before installing it.

“We’re not forcing any users to be bypassed, exploited or anything like that,” Mundorff said in a phone interview.  “At that point, if they do agree, it will allow us to make posts on their wall through our system.”

Mundorff claims his software is actually a benefit to Facebook and the Internet community at large because it is designed to also remove infections from some of the more popular bot and Trojan programs currently for sale on Hackforums, including Darkcomet, Cybergate, Blackshades and Andromeda (the latter being a competitor to the password-stealing ZeuS Trojan that hides behind Facebook comments). Mundorff maintains that his plugin will result in a positive experience for the average Facebook user, although he acknowledges that customers who purchase LilyJade can modify at will the link that “users” are forced to spread, and may at any time swap in links to malware or exploit sites. Continue reading →


20
Mar 12

Twitter Bots Target Tibetan Protests

Twitter bots — zombie accounts that auto-follow and send junk tweets hawking questionable wares and services — can be an annoyance to anyone who has even a modest number of followers. But increasingly, Twitter bots are being used as a tool to suppress political dissent, as evidenced by an ongoing flood of meaningless tweets directed at hashtags popular for tracking Tibetan protesters who are taking a stand against Chinese rule.

It’s not clear how long ago the bogus tweet campaigns began, but Tibetan sympathizers say they recently noticed that several Twitter hashtags related to the conflict — including #tibet and #freetibet — are now so constantly inundated with junk tweets from apparently automated Twitter accounts that the hashtags have ceased to become a useful way to track the conflict.

The discovery comes amid growing international concern over the practice of self-immolation as a means of protest in Tibet. According to the Associated Press, about 30 Tibetans have set themselves on fire since last year to protest suppression of their Buddhist culture and to call for the return of the Dalai Lama — their spiritual leader who fled during a failed 1959 uprising against Chinese rule.

I first heard about this trend from reader Erika Rand, who is co-producing a feature-length documentary about Tibet called State of Control. Rand said she noticed the tweet flood and Googled the phenomenon, only to find a story I wrote about a similar technique deployed in Russia to dilute Twitter hashtags being used by citizens protesting last year’s disputed parliamentary elections there.

“We first discovered these tweets looking at Twitter via the web, then looked at TweetDeck to see how quickly they were coming,” Rand said in an email to KrebsOnSecurity.com late last week. “They no longer appear when searching for Tibet on Twitter via the web, but are still flooding in fast via TweetDeck. This looks like an attempt to suppress news about recent activism surrounding Tibet. We’re not sure how long it’s been going on for. We noticed it last night, and it’s still happening now.” Continue reading →


15
Jul 11

How to Buy Friends and Deceive People

Want more friends and followers? Emerging enterprises will create them for you — for a price. An abundance of low-cost, freelance labor online is posing huge challenges for Internet companies trying to combat the growing abuse of their services, and has created a virtual testbed for emerging industries built to assist a range of cybercrime activities, new research shows.

Free services like Craigslist, Facebook, Gmail and Twitter have long sought to deter scammers and spammers by deploying technical countermeasures designed to prevent automated activity, such as the use of botnets to create new accounts en masse. These defenses typically require users to perform tasks that are difficult to automate, at least in theory, such as requiring that new accounts be verified by phone before activation.

But researchers from the University of California, San Diego found that these fraud controls increasingly are being defeated by freelance work arrangements: buyers “crowdsource” work by posting jobs they need done, and globally distributed workers bid on projects that they are willing to take on.

“The availability of this on-demand, for-hire contract market to do just about anything you can think of means it’s very easy for people to innovate around new scams,” said Stefan Savage, a UCSD computer science professor and co-author of the study.

The UCSD team examined almost seven years worth of data from freelancer.com, a popular marketplace for those looking for work. They found that 65-70 percent of the 84,000+ jobs offered for bidding during that time appeared to be for legitimate work such online content creation and Web programming. The remainder centered around four classes of what they termed “dirty” jobs, such as account registration and verification, social network linking (buying friends and followers), search engine optimization, and ad posting and bulk mailing.

“Though not widely appreciated, today there are vibrant markets for such abuse-oriented services,’” the researchers wrote. “In a matter of minutes, one can buy a thousand phone-verified Gmail accounts for $300, or a thousand Facebook ‘friends’ for $26 – all provided using extensive manual labor.”

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3
May 11

Advanced Persistent Tweets: Zero-Day in 140 Characters

The unceasing barrage of targeted email attacks that leverage zero-day software flaws to steal sensitive information from businesses and the U.S. government often are described as being ultra-sophisticated, almost ninja-like in stealth and anonymity. But according to expert analysis of several recent zero-day attacks – including the much publicized break-in at security giant RSA — the Chinese developers of those attack tools left clues aplenty about their identities and locations, with one apparent contender even Tweeting about having newly discovered a vulnerability days in advance of its use in the wild.

Zero-day threats are attacks which exploit security vulnerabilities that a software vendor learns about at the same time as the general public  does;   The vendor has “zero days” to fix the flaw before it gets exploited. RSA and others have labeled recent zero-day attacks as the epitome of the so-called “advanced persistent threat” (APT), a controversial term describing the daily onslaught of digital assaults launched by attackers who are considered highly-skilled, determined and possessed of a long-term perspective on their mission. Because these attacks often result in the theft of sensitive and proprietary information from the government and private industry, the details usually are shrouded in secrecy when law enforcement and national security investigators swoop in.

Open source information available about the tools used in recent attacks labeled APT indicates that some of the actors involved are doing little to cover their tracks: Not only are they potentially identifiable, they don’t seem particularly concerned about suffering any consequences from their actions.

Bragging rights may play a part in the attackers’  lack of duplicity. On Apr. 11, 2011, security experts began publishing information about a new zero-day attack that exploited a previously unknown vulnerability in Adobe‘s Flash Player software, a browser plug-in installed in 96 percent of the world’s Microsoft Windows PCs .  The exploit code was hidden inside a Microsoft Word document titled “Disentangling Industrial Policy and Competition Policy.doc,” and reportedly was emailed to an unknown number of U.S. government employees and contractors.

Four days earlier, on Apr. 7, an individual on Twitter calling himself “Yuange” and adopting the humble motto “No. 1 hacker in China top hacker in the world,” tweeted a small snippet of exploit code, apparently to signal that he had advance knowledge of the attack:

call [0x1111110+0x08].

It wasn’t long before malware researchers were extracting that exact string from the innards of a Flash exploit that was landing in email inboxes around the globe.

Tweeting a key snippet of code hidden in a zero-day exploit in advance of its public release may seem like the hacker equivalent of Babe Ruth pointing to the cheap seats right before nailing a home run. But investigators say the Chinese Internet address used to download the malicious files in the early hours of the April Flash zero-day attacks — 123.123.123.123 — was in some ways bolder than most because that address  would appear highly unusual and memorable to any reasonably vigilant network administrator.

This wasn’t the first time Yuange had bragged about advance knowledge of impending zero-day attacks. On Oct. 27, 2010, he boasted of authoring a zero-day exploit targeting a previously unknown vulnerability in Mozilla’s Firefox Web browser:

Wrote the firefox 0day. You may see “for(inx=0′inx<0×8964;inx++). You should know why 0×8964 here.

That same day, experts discovered that the Web site for the Nobel Peace Prize was serving up malicious software that exploited a new vulnerability in Firefox. An analysis of the attack code published by a member of Mozilla’s security team revealed the exact code snippet Yuange had tweeted.

On February 28, 2011, Yuange taunted on Twitter that new zero-day traps were being set:

ready? new flash 0day is on the way.

On Mar. 14, Adobe acknowledged that a new Flash flaw was being exploited via a booby-trapped Flash component tucked inside of Microsoft Excel files. Three days after that, EMC’s security division RSA dropped a bombshell: Secret files related to its widely used SecurID authentication tokens had been stolen in “an extremely sophisticated cyber attack.” A follow-up blog post from RSA’s Uri River two weeks later stated that the break-in was precipitated by the zero-day Adobe had warned about on Mar. 14, and that the lure used in the attack on RSA was an Excel file named “2011 Recruitment Plan.”

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