Krebs on Security

Hacked Via RDP: Really Dumb Passwords

December 13, 2013

Businesses spend billions of dollars annually on software and hardware to block external cyberattacks, but a shocking number of these same organizations shoot themselves in the foot by poking gaping holes in their digital defenses and then advertising those vulnerabilities to attackers. Today’s post examines an underground service that rents access to hacked PCs at organizations that make this all-too-common mistake.

Makost[dot]net is a service advertised on cybercrime forums which sells access to “RDPs”, mainly Microsoft Windows systems that have been configured (poorly) to accept “Remote Desktop Protocol” connections from the Internet. Windows ships with its own RDP interface built-in; to connect to another Windows desktop or server remotely, simply fire up the Remote Desktop Connection utility in Windows, type in the Internet address of the remote system, and enter the correct username and password for a valid user account on that remote system. Once the connection is made, you’ll see the remote computer’s desktop as if you were sitting right in front of it, and have access to all its programs and files.

Makhost[dot]net sells access to thousands of hacked RDP installations. Prices range from $3 to $10 based on a variety of qualities, such as the number of CPUs, the operating system version and the PC’s upload and download speeds.

Makost currently is selling access to more than 6,000 compromised RDP installations worldwide. As we can see from the screen shot above, hacked systems are priced according to a combination of qualities of the server:

city, state, country of host;
administrative or regular user rights;
operating system version;
number and speed of computer processors;
amount of system memory;
network download and upload speeds;
NAT or direct

KrebsOnSecurity was given a glimpse inside the account of a very active user of this service, an individual who has paid more than $2,000 over the past six months to purchase some 425 hacked RDPs. I took the Internet addresses in this customer’s purchase history and ran WHOIS database lookups on them all in a bid to learn more about the victim organizations. As expected, roughly three-quarters of those addresses told me nothing about the victims; the addresses were assigned to residential or commercial Internet service providers.

But the WHOIS records turned up the names of businesses for approximately 25 percent of the addresses I looked up. The largest group of organizations on this list were in the manufacturing (21 victims) and retail services (20) industries. As I sought to categorize the long tail of other victim organizations, I was reminded of the Twelve Days of Christmas carol.

twelve healthcare providers;
ten education providers;
eight government agencies;
seven technology firms;
six insurance companies;
five law firms;
four financial institutions;
three architects;
two real estate firms;
and a forestry company (in a pear tree?)

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Help Bring Privacy Laws Into 21st Century

December 11, 2013

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Lost in the ongoing media firestorm over the National Security Agency’s domestic surveillance activities is the discussion about concrete steps to bring the nation’s communications privacy laws into the 21st Century. Under current laws that were drafted before the advent of the commercial Internet, federal and local authorities can gain access to mobile phone and many email records without a court-issued warrant. In this post, I’ll explain what federal lawmakers and readers can do to help change the status quo [tl;dr: if you’d rather skip the explanation and go right to the What Can You Do? section, click here]

The Center for Democracy & Technology, a policy think-tank based in Washington, D.C., has a concise and informative primer on the Electronic Communications Privacy Act (ECPA), the 1986 statute that was originally designed to protect Americans from Big Brother and from government overreach. Unfortunately, the law is now so outdated that it actually provides legal cover for the very sort of overreach it was designed to prevent.

Online messaging was something of a novelty when lawmakers were crafting the ECPA, which gave email moving over the network essentially the same protection as a phone call or postal letter. In short, it required the government to obtain a court-approved warrant to gain access to that information. But the Justice Department wanted different treatment for stored electronic communications. (Bear in mind that this was way before anyone was talking about “cloud” storage; indeed CDT notes that electronic storage of digital communications in 1986 was quite expensive, and it wasn’t unusual for email providers to delete messages that were more than a few months old).

CDT explains the bargain that was struck to accommodate the government’s concerns:

“Congress said that after 180 days email would no longer be protected by the warrant standard and instead would be available to the government with a subpoena, issued by a prosecutor or FBI agent without the approval of a judge,” CDT wrote. “At the same time, Congress concluded that, while the contents of communications must be highly protected in transit, the ‘transactional data’ associated with communications, such as dialing information showing what numbers you are calling, was less sensitive. ECPA allowed the government to use something less than a warrant to obtain this routing and signaling information.”

Fast-forward to almost 2014, and we find of course that most people store their entire digital lives “in the cloud.” This includes not only email, but calendar data, photos and other sensitive information. Big cloud providers like Google, Microsoft and Yahoo! have given users so much free storage space that hardly anyone has cause to delete their stuff anymore. Not only that, but pretty much everyone is carrying a mobile phone that can be used to track them and paint a fairly detailed account of their daily activities.

But here’s the thing that’s screwy about ECPA: If you’re the kind of person who stores all that information on your laptop, the government can’t get at it without a court-ordered warrant. Leave it in the hands of email, mobile and cloud data providers, however, and it’s relatively easy pickings for investigators.

“There has been an interpretation of the law from the government that says any document stored in the cloud can be accessed with a subpoena, regardless of how old it is,” said Mark Stanley, a communications strategist with CDT. “The government can access emails over 180 days old with just a subpoena. “We also know that the [Justice Department] has interpreted the law to say that any emails that are opened — regardless of how old they are — can be accessed without a warrant.”

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Zero-Day Fixes From Adobe, Microsoft

December 10, 2013

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Adobe and Microsoft today each separately released security updates to remedy zero-day bugs and other critical vulnerabilities in their software. Adobe issued fixes for its Flash and Shockwave players, while Microsoft pushed out 11 updates addressing at least two dozen flaws in Windows and other software.

Five of today’s 11 update bundles earned Microsoft’s “critical” rating, meaning that the vulnerabilities those patches fix can be exploited remotely by malware or miscreants without any help from users. At the top of the priority list for Windows users should be MS13-096, a patch that plugs a critical zero-day security hole in certain versions of Windows and Office. Microsoft first warned about this flaw on Nov. 5.

Microsoft also is urging customers and system administrators to prioritize two other critical fixes: MS13-097, a cumulative patch for Internet Explorer (all versions), and MS13-099, which fixes a dangerous scripting issue in Windows. All three of these patches fix bugs that Microsoft says are likely to be exploited by attackers in the near future.

Ross Barrett, senior manager of security engineering at Rapid7, points out a noteworthy patch (MS13-104) for users of Microsoft Office 2013’s “cloud” services, which apparently fixes another vulnerability that is actively being exploited. “This information disclosure issue affects the Office ‘client’ and could allow an attacker to hijack an authentication token and gain access to documents stored in cloud resources,” Barrett said.

For more information on today’s updates, see the roundups at Microsoft’s Technet Blog, the SANS Internet Storm Center Diary, and the Qualys blog.

ADOBE FLASH AND SHOCKWAVE UPDATES

Adobe has issued a patch for its Flash Player software that addresses at least two security holes, including a vulnerability that is already under active attack. Adobe said it is aware of reports of an exploit designed to trick the user into opening a Microsoft Word document with malicious Flash (.swf) content. The company credits researcher Attila Suszter for reporting the flaw; more information about this bug is available at Suszter’s blog.

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Who Is Paunch?

December 9, 2013

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Last week, the world got the first glimpses of a man Russian authorities have accused of being “Paunch,” a computer crime kingpin whose “Blackhole” crimeware package has fueled an explosion of cybercrime over the past several years. So far, few details about the 27-year-old defendant have been released, save for some pictures of a portly lad and a list of his alleged transgressions. Today’s post follows a few clues from recent media coverage that all point to one very likely identity for this young man.

Dmitry Fedotov from Togliatti, Russia.

The first story in the Western media about Paunch’s arrest came on Oct. 8, 2013 from Reuters, which quoted an anonymous former Russian police detective. But the initial news of Paunch’s arrest appears to have broken on Russian news blogs several days earlier. On Oct. 5, Russian news outlet neslushi.info posted that a hacker by the name of Dmitry Fedotov had been arrested the night before in Togliatti, a city in Samara Oblast, Russia. The story noted that Fedotov was wanted for creating a program that was used by various organized crime groups to siphon roughly 26 billion rubles (USD $866 million) from unnamed banks. Another story from local news site Samara.ru on Oct. 8 references a Dmitry F. from Togliatti.

This is an interesting lead; last week’s story on Paunch cited information released by Russian forensics firm Group-IB, which did not include Paunch’s real name but said that he resided in Togliatti.

Fast-forward to this past week, and we see out of the Russian publication Vedomosti.ru a story stating that Paunch owned his own Web-development company. That story also cited Group-IB saying that Paunch had experience as an advertising manager. This Yandex profile includes a resume for a Dmitry Fedotov from Togliatti who specializes in Web programming and advertising, and lists “hack money” under his “professional goals” section. It also states that Fedotov attended the Volga State University of Service from 2003-2005.

That Yandex profile for Fedotov says his company is a site called “neting.ru,” a Web development firm. The current Web site registration records for that domain do not include an owner’s name, but a historic WHOIS record ordered from domaintools.com shows that neting.ru was originally registered in 2004 by a Dmitry E. Fedotov, using the email addresses box@neting.ru and tolst86@mail.ru.

A cached contact page for neting.ru at archive.org shows the same box@neting.ru email address and includes an ICQ instant messenger address, 360022. According to ICQ.com, that address belongs to a user who picked the nickname “tolst,” which roughly translates to “fatty.”

A user who picked the nickname “tolst” or “fatty” posted this image of his new Porsche Cayenne in March 2013

This brings up something I want to address from last week’s story: Some readers said they thought it was insensitive of me to point out that Paunch himself called attention to his most obvious physical trait. But this seems to be a very important detail: Paunch had a habit of picking self-effacing nicknames.

The pictures of Paunch released by Group-IB show a heavyset young man, and Paunch seems to have picked nicknames that called attention to his size. One email address known to have been used by the Blackhole author was “paunchik@googlemail.com” (“paunchik” means “doughnut” in Russian). Blackhole exploit kit users who wished to place their advertisements in the crimeware kit itself so that other customers would see the ads were instructed to pay for the advertisements by sending funds to a Webmoney purse Z356971281174, which is tied to the Webmoney ID 561656619879; that Webmoney ID uses the alias “puzan,” a variant of the Russian word пузо, or “potbelly.”

Turns out, “tolst” was a common nickname picked by Paunch. We can see a user who picked that same “tolst” nickname posting in a Russian car forum in March 2013 about his new ride: a white Porsche Cayenne. According to this photo released by Group-IB, Paunch also owned a white Porsche Cayenne. Tolst posted pictures of the interior of his Porsche here.

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Meet Paunch: The Accused Author of the BlackHole Exploit Kit

December 6, 2013

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In early October, news leaked out of Russia that authorities there had arrested and charged the malware kingpin known as “Paunch,” the alleged creator and distributor of the Blackhole exploit kit. Today, Russian police and computer security experts released additional details about this individual, revealing a much more vivid picture of the cybercrime underworld today.

Paunch, the accused creator of the Blackhole Exploit Kit, stands in front of his Porsche Cayenne.

A statement released by the Russian Interior Ministry (MVD) — the entity which runs the police departments in each Russian city — doesn’t include Paunch’s real name, but it says the Blackhole exploit kit creator was arrested in October along with a dozen other individuals who allegedly worked to sell, develop and profit from the crimeware package.

Russian security and forensics firm Group-IB, which assisted in the investigation, released additional details, including several pictures of the 27-year-old accused malware author. According to Group-IB, Paunch had more than 1,000 customers and was earning $50,000 per month from his illegal activity. The image at right shows Paunch standing in front of his personal car, a Porsche Cayenne.

First spotted in 2010, BlackHole is commercial crimeware designed to be stitched into hacked or malicious sites and exploit a variety of Web-browser vulnerabilities for the purposes of installing malware of the customer’s choosing. The price of renting the kit ran from $500 to $700 each month. For an extra $50 a month, Paunch also rented customers “crypting” services; cryptors are designed to obfuscate malicious software so that it remains undetectable by antivirus software.

If the 27-year-old pictured here truly is Paunch, he certainly lived up to his nickname.

Paunch worked with several other cybercriminals to purchase new exploits and security vulnerabilities that could be rolled into Blackhole and help increase the success of the software. Paunch bought the exploits to fund a pricier ($10,000/month) and more exclusive exploit pack called “Cool Exploit Kit.”

As documented on this blog in January 2013 (see Crimeware Author Funds Exploit Buying Spree), Paunch contracted with a third-party exploit broker who announced that he had a $100,000 budget for buying new, previously undocumented “zero-day” vulnerabilities.

Not long after that story, the individual with whom Paunch worked to purchase those exclusive exploits — a miscreant who uses the nickname “J.P. Morgan” — posted a message to the Darkode[dot]com crime forum, stating that he was doubling his exploit-buying budget to $200,000.

In October, shortly after news of Paunch’s arrest leaked to the media, J.P. Morgan posted to Darkode again, this time more than doubling his previous budget — to $450,000.

“Dear ladies and gentlemen! In light of recent events, we look to build a new exploit kit framework. We have budgeted $450,000 to buy vulnerabilities of a browser and its plugins, which will be used only by us afterwards! ”

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ZeroAccess Botnet Down, But Not Out

December 5, 2013

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Europol, Microsoft Kneecap Click-Fraud Botnet

Authorities in Europe joined Microsoft Corp. this week in disrupting “ZeroAccess,” a vast botnet that has enslaved more than two million PCs with malicious software in an elaborate and lucrative scheme to defraud online advertisers.

The action comes partly from Europol’s European Cybercrime Center (EC3), as well as law enforcement cybercrime units from Germany, Latvia, Switzerland and the Netherlands, countries that hosted many of the Internet servers used to control the ZeroAccess botnet.

In tandem with the law enforcement moves in Europe, Microsoft filed a civil lawsuit to unmask eight separate cybercriminals thought to be operating the giant botnet, and to block incoming and outgoing communications between infected PCs in the United States and those 18 control servers, according to a statement released by EC3.

The malware the powers the botnet, also known as “ZAccess” and “Sirefef,” is a complex threat that has evolved significantly since its inception in 2009. It began as a malware delivery platform that was used to spread other threats, such as fake antivirus software (a.k.a. “scareware”).

In recent years, however, the miscreants behind ZeroAccess rearchitected the botnet so that infected systems were forced to perpetrate a moneymaking scheme known as “click fraud” — the practice of fraudulently generating clicks on ads without any intention of fruitfully interacting with the advertiser’s site.

Maps of ZeroAccess infected PCs in Texas. Source: botnetlegalnotice.com

It remains unclear how much this coordinated action will impact the operations of ZeroAccess over the long term. Early versions of ZeroAccess relied on a series of control servers to receive updates, but recent versions of the botnet malware were designed to make the network as a whole more resilient and resistant to targeted takedowns such as the one executed this week.

Specifically, ZeroAccess employs a peer-to-peer (P2P) architecture in which new instructions and payloads are distributed from one infected host to another. P2P-based botnets are designed to eliminate a single point of failure, so that if one node used to control the botnet is knocked offline, the remainder of the botnet can still function.

The actions this week appear to have targeted the servers that deliver a specific component of ZeroAccess that gives infected systems new instructions on how to defraud various online advertisers — including Microsoft. While this effort will not disable the ZeroAccess botnet (the infected systems will likely remain infected), it should allow Microsoft to determine which online affiliates and publishers are associated with the miscreants behind ZeroAccess, since those publishers will have stopped sending traffic directly after the takedown occurred.

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How Many Zero-Days Hit You Today?

December 5, 2013

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On any given day, nation-states and criminal hackers have access to an entire arsenal of zero-day vulnerabilities — undocumented and unpatched software flaws that can be used to silently slip past most organizations’ digital defenses, new research suggests. That sobering conclusion comes amid mounting evidence that thieves and cyberspies are ramping up spending to acquire and stockpile these digital armaments.

Security experts have long suspected that governments and cybercriminals alike are stockpiling zero-day bugs: After all, the thinking goes, if the goal is to exploit these weaknesses in future offensive online attacks, you’d better have more than a few tricks up your sleeve because it’s never clear whether or when those bugs will be independently discovered by researchers or fixed by the vendor. Those suspicions were confirmed very publicly in 2010 with the discovery of Stuxnet, a weapon apparently designed to delay Iran’s nuclear ambitions and one that relied upon at least four zero-day vulnerabilities.

Documents recently leaked by National Security Agency whistleblower Edward Snowden indicate that the NSA spent more than $25 million this year alone to acquire software vulnerabilities from vendors. But just how many software exploits does that buy, and what does that say about the number of zero-day flaws in private circulation on any given day?

These are some of the questions posed by Stefan Frei, research director for Austin, Texas-based NSS Labs. Frei pored over reports from and about some of those private vendors — including boutique exploit providers like Endgame Systems, Exodus Intelligence, Netragard, ReVuln and VUPEN — and concluded that jointly these firms alone have the capacity to sell more than 100 zero-day exploits per year.

According to Frei, if we accept that the average zero-day exploit persists for about 312 days before it is detected (an estimate made by researchers at Symantec Research Labs), this means that these firms probably provide access to at least 85 zero-day exploits on any given day of the year. These companies all say they reserve the right to restrict which organizations, individuals and nation states may purchase their products, but they all expressly do not share information about exploits and flaws with the affected software vendors.

Frei’s minimum estimate of exploits offered by boutique exploit providers each year.

KNOWN UNKNOWNS

That approach stands apart from the likes of HP TippingPoint‘s Zero-Day Initiative (ZDI) and Verisign‘s iDefense Vulnerability Contributor Program (VCP), which pay researchers in exchange for the rights to their vulnerability research. Both ZDI and iDefense also manage the communication with the affected vendors, ship stopgap protection for the vulnerabilities to their customers, and otherwise keep mum on the flaws until the vendor ships an update to fix the bugs.

Frei also took stock of the software vulnerabilities collected by these two companies, and found that between 2010 and 2012, the ZDI and VCP programs together published 1,026 flaws, of which 425 (44 percent) targeted flaws in Microsoft, Apple, Oracle, Sun and Adobe products. The average time from purchase to publication was 187 days.

“On any given day during these three years, the VCP and ZDI programs possessed 58 unpublished vulnerabilities affecting five vendors, or 152 vulnerabilities total,” Frei wrote in a research paper released today.

Frei notes that the VCP and ZDI programs use the information they purchase only for the purpose of building better protection for their customers, and since they share the information with the software vendors in order to develop and release patches, the overall risk is comparatively low. Also, the vulnerabilities collected and reported by VCP and ZDI are not technically zero-days, since one important quality of a zero-day is that it is used in-the-wild to attack targets before the responsible vendor can ship a patch to fix the problem.

In any case, Frei says his analysis clearly demonstrates that critical vulnerability information is available in significant quantities for private groups, for extended periods and at a relatively low cost.

“So everybody knows there are zero days, but when we talk to C-Level executives, very often we find that these guys don’t have a clue, because they tell us, ‘Yeah, but we’ve never been compromised’,” Frei said in an interview. “And we always ask them, ‘How do you know?'”

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Simple But Effective Point-of-Sale Skimmer

December 3, 2013

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Point-of-sale (POS) skimmers — fraud devices made to siphon bank card and PIN data at the cash register — have grown in sophistication over the years: A few months back, this blog spotlighted a professionally made point-of-sale skimmer that involved some serious hacking inside the device. Today’s post examines a comparatively simple but effective POS skimmer that is little more than a false panel which sits atop the PIN pad and above the area where customers swipe their cards.

In scams, as with most things in life, there is a certain elegance in simplicity. This is doubly true with ATM and credit card skimmer scams: The more components and electronics involved, the greater the chance that the fraud devices will malfunction, lose juice, or else be detected too quickly. In fact, some of the most elegant skimming attacks I’ve seen to date never even touched the cash machine, and relied on very basic components.

Recently, I encountered a fraudster selling a remarkably simple but brilliant POS skimming device that can be installed and removed in the blink of an eye. This video, which was produced by a fraudster who sells these devices for thousands of dollars on semi-private underground forums, shows a late-model Verifone point-of-sale device retrofitted with a skimmer overlay. The underside of the device (not pictured) includes a tiny battery and flash storage card that allows the fake PIN pad to capture the key presses, and record the data stored on the magnetic stripe of each swiped card.

Such a device would be an enticing buy for a crooked employee at a retail store. It might even be installed surreptitiously by thieves posing as customers at a retail establishment. Last month, this blog featured a story about several fraudsters in Florida who did just that, installing hardware-based register skimmers at Nordstrom department stores while co-conspirators distracted sales personnel.

For more on ATM and POS skimmers, check out my series: All About Skimmers.

Important Security Update for D-Link Routers

December 2, 2013

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D-Link has released an important security update for some of its older Internet routers. The patch closes a backdoor in the devices that could let attackers seize remote control over vulnerable routers.

D-Link DI-524 router.

The update comes roughly seven weeks after researcher Craig Heffner discovered and blogged about a feature or bug built into at least eight different models of D-Link routers that could allow an attacker to log in as administrator and change the router’s settings. Although the router models affected are fairly old, there are almost certainly plenty of these still in operation, as routers tend to be set-it-and-forget-it devices that rarely get replaced or updated unless they stop working.

According to Heffner, an attacker who identified a vulnerable router would need merely to set his browser’s user agent string as “xmlset_roodkcableoj28840ybtide”, and he could log in to the router’s administrative interface without any authentication. Heffer later updated his blog post with a proof-of-concept illustrating how attackers also could use the bug to upload arbitrary code to the vulnerable devices.

On Nov. 28, D-Link released a series of updates to fix the problem. Updates are available for the following models:

DI-524
DI-524UP
DIR-100
DIR-120
DI-604UP
DI-604+
DI-624S
TM-G5240

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An Anti-Fraud Service for Fraudsters

November 26, 2013

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Many online businesses rely on automated fraud detection tools to weed out suspicious and unauthorized purchases. Oddly enough, the sorts of dodgy online businesses advertised by spam do the same thing, only they tend to use underground alternatives that are far cheaper and tuned to block not only fraudulent purchases, but also “test buys” from security researchers, law enforcement and other meddlers.

One anti-fraud measure commonly used in e-commerce is the address verification service (AVS), which seeks to verify the address of a person claiming to own a credit card. Some business employ additional “geo-IP” checks, which try to determine the geographical location of Website visitors based on their Internet addresses, and then match that with the billing address provided by the customer.

The trouble with these services is that they can get pricey in a hurry, and they’re often sold by the very companies that spammers are trying to outsmart. Enter services like fraudcheck[dot]cc: This service, run by an established spammer on a semi-private cybercrime forum, performs a multitude of checks on each transaction, apparently drawing on accounts from different, legitimate anti-fraud services. It accepts payment solely via WebMoney, a virtual currency that is popular in Russia and Eastern Europe.

fraudcheck[dot]cc resells bundles of anti-fraud services from legitimate providers like MaxMind.

This fraudster-friendly antifraud service does the following analysis:

Queries the geo-IP location from four distinct sources;
Calculates the billing ZIP code distance from the customer’s geo-IP coordinates;
Checks the customer’s Internet address against lists of known proxies that are used to mask an Internet user’s true location, and assigns a “risk score” of zero to 4.2 (the higher the number, the greater the certainty that the purchase was made via a proxy).
Generates a “fraud score” from 0-100 to rate the riskiness of the transaction (100 being the riskiest)

The bulk of the fraud checks appear to be conducted through [hijacked?] accounts at MaxMind.com, a Waltham, Mass. company that screens more than 45 million online transactions per month for 7,000 companies. MaxMind sells a suite of legitimate anti-fraud solutions, including two specifically called out in the screen shot above (minFraud and GeoIP).

As detailed in this white paper (PDF), MaxMind’s minFraud service checks for a number of potential risk factors, such as whether the customer is using a free Webmail account, or there is a mismatch in the shipping and billing address. It also looks to see whether the customer is paying with a card from a known bank. Failure to identify a “bank identification number” (BIN) — the first six digits of any card — may indicate the customer is paying with a prepaid card and thus trying to mask their identity or location.

Based on the combined results of these tests, MaxMind’s service will assign a “fraud score” from 0 to 100, indicating the service’s best guess about whether the transaction should be allowed or declined. In the example from the screenshot above, it’s not clear why the service assigned such a high fraud score (96.84) to the transaction in question — perhaps because the service could not identify the bank that issued the card used in the transaction and determined that it was a prepaid card.

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