Krebs on Security

Should SaaS Companies Publish Customers Lists?

May 22, 2017

A few weeks back, HR and financial management firm Workday.com sent a security advisory to customers warning that crooks were sending targeted malware phishing attacks at customers. At the same time, Workday is publishing on its site a list of more than 800 companies that use its services, making it relatively simple for attackers to chose their targets. This post examines whether it makes sense for software-as-a-service (SaaS) companies to publish lists of their customers when those customers are actively under siege from phishers impersonating the SaaS provider.

At its most basic, security always consists of trade-offs. Many organizations find a natural tension between marketing and security. The security folks warn that publishing too much information about how the company does business and with whom makes it way too easy for phishers and other scammers to target your customers.

A screenshot of a phishing lure used to target Workday customers.

The marketing folks, quite naturally, often have a different perspective: The benefits of publishing partner data far outweigh the nebulous risks that someone may abuse this information.

So the question is, at what point does marketing take a backseat to security at SaaS firms when their customers are being phished? Is it even reasonable to think that determined attackers would be deterred if they had to pore through press releases and other public data to find a target list?

When I first approached Workday in researching this column, I did so in regard to an alert they emailed customers earlier this month. In the alert, Workday warned that customers using single-factor authentication to access Workday were being targeted by email phishing campaigns. The company said there was no evidence to suggest the phishing a result of the Workday service or infrastructure, but rather it was the result of phishing emails where individuals at customer organizations shared login credentials with a malicious third party. In short, they’d been phished.

A portion of the phishing alert that Workday sent to its customers.

Workday advised customers to take advantage of the company’s two-factor authentication systems, and to enable secondary approvals for all important transactions.

All good advice, but I also challenged the company that it maybe wasn’t the best idea to also publish a tidy list of more than 800 customers on its Web site. I also noted that Workday’s site makes it simple to find an HTML template for targeted phishing campaigns. Just take one of the companies listed on its site and enter the name in the Workday Sign-in search page. Selecting Netflix from the list of Workday customers, for example, we can find Netflix’s login page:

Netflix’s sign-in page at Workday.com.

That link opens up a page that allows Netflix customers to login to Workday using Google’s OAuth system for linking third-party apps to Google accounts. It’s a good thing we haven’t recently seen targeted phishing attacks that mimic this precise process to hijack Google accounts.

Oh wait, something very similar just happened earlier this month. In the first week of May, phishers began sending Google Docs phishing campaigns via Gmail disguised as an offer to share a document. Recipients who fell for the ruse ended up authorizing an app from Google’s OAuth authentication interface — i.e., handing crooks direct access to their accounts.

Before I go further, let me just say that it is not my intention to single out Workday in this post: There are plenty of other companies in its exact same position. The question I want to explore is at what point does marketing get trumped by security? For me, the juxtaposition between Workday’s warning and its priming the pump for phishers at the same time seemed off.

Workday wasn’t swayed by my logic, and they referred me to an industry analyst for the finer points of that perspective. Michael Krigsman, a tech analyst and host at cxotalk.com, said he often advises smaller companies that may be less sophisticated in their marketing strategies to publish a list of customers on their home pages.

“Even when it comes to larger companies like Workday, they’re selling so many seats that this information is highly public knowledge and very easy to get,” Krigsman said. “If you’re interested in Workday’s customer lists, for example, you can easily find that out because Workday puts out press releases, their customers put out press releases, and this gets picked up in the trade press.” Continue reading →

Private Eye Allegedly Used Leaky Goverment Tool in Bid to Find Tax Data on Trump

May 22, 2017

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In March 2017, KrebsOnSecurity warned that thieves who perpetrate tax refund fraud with the U.S. Internal Revenue Service were leveraging a widely-used online student loan tool to find critical data on consumers that allows them to claim huge refunds with the IRS in someone else’s name. This week, it emerged that a Louisiana-based private investigator is being charged with using the same online tool to glean tax data on then-presidential candidate Donald J. Trump.

A story today at Diverseeducation.com points to court filings in the U.S. District Court for the Middle District of Louisiana, in which local private eye Jordan Hamlett is accused by federal prosecutors of abusing an automated tool at the U.S. Department of Education website that is designed to make it easier for families to complete the Education Department’s Free Application for Federal Student Aid (FAFSA) — a lengthy form that serves as the starting point for students seeking federal financial assistance to pay for college or career school.

Grand jury findings in a sealed case against Louisiana private investigator Jordan Hamlett.

In November 2016, Hamlett — the owner of Baton Rouge-based Averlock Investigations — was indicted on felony charges of trying to glean then President-Elect Trump’s “adjusted gross income,” or AGI, using the FAFSA online tool. In the United States, the AGI is an individual’s total gross income minus specific deductions. Diverse Education’s Jamaal Abdul-Alim cites sources saying the accused may have been trying to get Trump’s tax records.

In any event, he failed, according to prosecutors. Last month, the IRS announced that the Education Department was disabling the FAFSA lookup tool because it was being abused by tax fraudsters.

According to Diverse Education, hints about the case against Hamlett came out earlier this month in an IRS oversight hearing before the U.S. House committee on oversight and government reform. At that hearing, “Timothy P. Camus, deputy inspector general for investigations at the Treasury Inspector General for Tax Administration, or TIGTA, alluded to the Hamlett case but did not mention Hamlett by name, nor did he indicate that then-presidential candidate Trump was the target,” Abdul-Alim writes. “Instead, Camus only mentioned that TIGTA ‘detected an attempted access to the AGI of a prominent individual.'”

Attempts to reach Hamlett for comment have been unsuccessful so far, and the complaint against him remains sealed. However, KrebsOnSecurity obtained a response on Nov. 10, 2016 from U.S. Attorney J. Walter Green that lays out the basic facts in the case. A copy of that document is here (PDF).

It’s interesting to note that this wasn’t the only time U.S. government authorities detected someone trying to access Trump’s AGI information. According to the government’s response, the alleged unauthorized attempt at Trump’s AGI data being attributed to Hamlett occurred on Sept. 13, 2016.

In TIGTA Deputy Inspector General Camus’ testimony to the House committee (PDF), he said his office detected a second attempt to access the same “prominent individual’s” AGI data via the FAFSA online lookup in November 2016, although the testimony doesn’t say whether that attempt was successful.

Amazingly, it wasn’t until an IRS employee on February 27, 2017 complained that his personal data was stolen via the FAFSA tool that the IRS moved to restrict online access to the service, according to response to committee questioning from IRS Chief Information Officer S. Gina Garza. Continue reading →

Fraudsters Exploited Lax Security at Equifax’s TALX Payroll Division

May 18, 2017

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Identity thieves who specialize in tax refund fraud had big help this past tax year from Equifax, one of the nation’s largest consumer data brokers and credit bureaus. The trouble stems from TALX, an Equifax subsidiary that provides online payroll, HR and tax services. Equifax says crooks were able to reset the 4-digit PIN given to customer employees as a password and then steal W-2 tax data after successfully answering personal questions about those employees.

In a boilerplate text sent to several affected customers, Equifax said the unauthorized access to customers’ employee tax records happened between April 17, 2016 and March 29, 2017.

Beyond that, the extent of the fraud perpetrated with the help of hacked TALX accounts is unclear, and Equifax refused requests to say how many consumers or payroll service customers may have been impacted by the authentication weaknesses.

Equifax's TALX -- now called Equifax Workforce Solutions -- aided tax thieves by relying on outdated and insufficient consumer authentication methods.

Equifax’s subsidiary TALX — now called Equifax Workforce Solutions — aided tax thieves by relying on outdated and insufficient consumer authentication methods.

Thanks to data breach notification laws in nearly all U.S. states now, we know that so far at least five organizations have received letters from Equifax about a series of incidents over the past year, including defense contractor giant Northrop Grumman; staffing firm Allegis Group; Saint-Gobain Corp.; Erickson Living; and the University of Louisville.

A snippet from TALX’s letter to the New Hampshire attorney general (PDF) offers some insight into the level of security offered by this wholly-owned subsidiary of Equifax. In it, lawyers for TALX downplay the scope of the breach even as they admit the company wasn’t able to tell exactly how much unauthorized access to tax records may have occurred.

“TALX believes that the unauthorized third-party(ies) gained access to the accounts primarily by successfully answering personal questions about the affected employees in order to reset the employees’ pins (the password to the online account portal),” wrote Nicholas A. Oldham, an attorney representing TALX. “Because the accesses generally appear legitimate (e.g., successful use of login credentials), TALX cannot confirm forensically exactly which accounts were, in fact, accessed without authorization, although TALX believes that only a small percentage of these potentially affected accounts were actually affected.”

ANALYSIS

Generally. Forensically. Exactly. Potentially. Actually. Lots of hand-waving from the TALX/Equifax suits. But Equifax should have known better than to rely on a simple PIN for a password, says Avivah Litan, a fraud analyst with Gartner Inc.

“That’s so 1990s,” Litan said. “It’s pretty unbelievable that a company like Equifax would only protect such sensitive data with just a PIN.”

Litan said TALX should have required customers to use stronger two-factor authentication options, such as one-time tokens sent to an email address or mobile device (as Equifax now says TALX is doing — at least with those we know were notified about possible employee account abuse).

The big consumer credit bureaus like Equifax, Experian, Innovis and Trans Union are all regulated by the Fair Credit Reporting Act (FCRA), which strives to promote accuracy, fairness and privacy for data used by consumer reporting agencies. But Litan said there are no federal requirements that credit bureaus use stronger authentication for access to consumer data — such as two-factor authentication.

“There’s about 500 percent more protection for credit card data right now than there is for identity data,” Litan said. “And yet I don’t know of one document from the federal government that spells out how these credit bureaus and other companies have to protect PII (personally identifiable information).” Continue reading →

Breach at DocuSign Led to Targeted Email Malware Campaign

May 15, 2017

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DocuSign, a major provider of electronic signature technology, acknowledged today that a series of recent malware phishing attacks targeting its customers and users was the result of a data breach at one of its computer systems. The company stresses that the data stolen was limited to customer and user email addresses, but the incident is especially dangerous because it allows attackers to target users who may already be expecting to click on links in emails from DocuSign.

San Francisco-based DocuSign warned on May 9 that it was tracking a malicious email campaign where the subject line reads, “Completed: docusign.com – Wire Transfer Instructions for recipient-name Document Ready for Signature.” The missives contained a link to a downloadable Microsoft Word document that harbored malware.

A typical DocuSign email. Image: DocuSign.

The company said at the time that the messages were not associated with DocuSign, and that they were sent from a malicious third-party using DocuSign branding in the headers and body of the email. But in an update late Monday, DocuSign confirmed that this malicious third party was able to send the messages to customers and users because it had broken in and stolen DocuSign’s list of customers and users.

“As part of our ongoing investigation, today we confirmed that a malicious third party had gained temporary access to a separate, non-core system that allows us to communicate service-related announcements to users via email,” DocuSign wrote in an alert posted to its site. “A complete forensic analysis has confirmed that only email addresses were accessed; no names, physical addresses, passwords, social security numbers, credit card data or other information was accessed. No content or any customer documents sent through DocuSign’s eSignature system was accessed; and DocuSign’s core eSignature service, envelopes and customer documents and data remain secure.”

The company is asking people to forward any suspicious emails related to DocuSign to spam@docusign.com, and then to delete the missives. Continue reading →

Global ‘Wana’ Ransomware Outbreak Earned Perpetrators $26,000 So Far

May 13, 2017

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As thousands of organizations work to contain and clean up the mess from this week’s devastating Wana ransomware attack, the fraudsters responsible for releasing the digital contagion are no doubt counting their earnings and congratulating themselves on a job well done. But according to a review of the Bitcoin addresses hard-coded into Wana, it appears the perpetrators of what’s being called the worst ransomware outbreak ever have made little more than USD $26,000 so far from the scam.

Victims of the Wana ransomware will see this lock screen demanding a $300 ransom to unlock all encrypted files.

The Wana ransomware became a global epidemic virtually overnight this week, after criminals started distributing copies of the malware with the help of a security vulnerability in Windows computers that Microsoft patched in March 2017. Infected computers have all their documents and other important user files scrambled with strong encryption, and victims without access to good backups of that data have two choices: Kiss the data goodbye, or pay the ransom — the equivalent of approximately USD $300 worth of the virtual currency Bitcoin.

According to a detailed writeup on the Wana ransomware published Friday by security firm Redsocks, Wana contains three bitcoin payment addresses that are hard-coded into the malware. One of the nice things about Bitcoin is that anyone can view all of the historic transactions tied a given Bitcoin payment address. As a result, it’s possible to tell how much the criminals at the helm of this crimeware spree have made so far and how many victims have paid the ransom.

A review of the three payment addresses hardcoded into the Wana ransomware strain indicates that these accounts to date have received 100 payments totaling slightly more than 15 Bitcoins — or approximately $26,148 at the current Bitcoin-to-dollars exchange rate. Continue reading →

Microsoft Issues WanaCrypt Patch for Windows 8, XP

May 13, 2017

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Microsoft Corp. today took the unusual step of issuing security updates to address flaws in older, unsupported versions of Windows — including Windows XP and Windows 8. The move is a bid to slow the spread of the WanaCrypt ransomware strain that infected tens of thousands of Windows computers virtually overnight this week.

A map tracking the global spread of the Wana ransomware strain. Image: Malwaretech.com.

On Friday, May 12, countless organizations around the world began fending off attacks from a ransomware strain variously known as WannaCrypt, WanaDecrypt and Wanna.Cry. Ransomware encrypts a victim’s documents, images, music and other files unless the victim pays for a key to unlock them.

It quickly became apparent that Wanna was spreading with the help of a file-sharing vulnerability in Windows. Microsoft issued a patch to fix this flaw back in March 2017, but organizations running older, unsupported versions of Windows (such as Windows XP) were unable to apply the update because Microsoft no longer supplies security patches for those versions of Windows.

The software giant today made an exception to that policy after it became clear that many organizations hit hardest by Wanna were those still running older, unsupported versions of Windows.

“Seeing businesses and individuals affected by cyberattacks, such as the ones reported today, was painful,” wrote Phillip Misner, principal security group manager at the Microsoft Security Response Center. “Microsoft worked throughout the day to ensure we understood the attack and were taking all possible actions to protect our customers.”

The update to address the file-sharing bug that Wanna is using to spread is now available for Windows XP, Windows 8, and Windows Server 2003 via the links at the bottom of this advisory.

On Friday, at least 16 hospitals in the United Kingdom were forced to divert emergency patients after computer systems there were infected with Wanna. According to multiple stories in the British media, approximately 90 percent of care facilities in the U.K.’s National Health Service are still using Windows XP – a 16-year-old operating system.

According to a tweet from Jakub Kroustek, a malware researcher with security firm Avast, the company’s software has detected more than 100,000 instances of the Wana ransomware.

For advice on how to harden your systems against ransomware, please see the tips in this post.

U.K. Hospitals Hit in Widespread Ransomware Attack

May 12, 2017

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At least 16 hospitals in the United Kingdom are being forced to divert emergency patients today after computer systems there were infected with ransomware, a type of malicious software that encrypts a victim’s documents, images, music and other files unless the victim pays for a key to unlock them.

It remains unclear exactly how this ransomware strain is being disseminated and why it appears to have spread so quickly, but there are indications the malware may be spreading to vulnerable systems through a security hole in Windows that was recently patched by Microsoft.

The ransom note left behind on computers infected with the Wanna Decryptor ransomware strain. Image: BleepingComputer.

In a statement, the U.K.’s National Health Service (NHS) said a number of NHS organizations had suffered ransomware attacks.

“This attack was not specifically targeted at the NHS and is affecting organizations from across a range of sectors,” the NHS said. “At this stage we do not have any evidence that patient data has been accessed.”

According to Reuters, hospitals across England are diverting patients requiring emergency treatment away from the affected hospitals, and the public is being advised to seek medical care only for acute medical conditions.

NHS said the investigation is at an early stage but the ransomware that hit at least 16 NHS facilities is a variant of Wana Decryptor (a.k.a. “WannaCry“), a ransomware strain that surfaced roughly two weeks ago.

Lawrence Abrams, owner of the tech-help forum BleepingComputer, said Wana Decryptor wasn’t a big player in the ransomware space until the past 24 hours, when something caused it to be spread far and wide very quickly.

“It’s been out for almost two weeks now, and until very recently it’s just been sitting there,” Abrams said. “Today, it just went nuts. This is by far the biggest outbreak we have seen to date.”

For example, the same ransomware strain apparently today also hit Telefonica, one of Spain’s largest telecommunications companies. According to an article on BleepingComputer, Telefonica has responded by “desperately telling employees to shut down computers and VPN connections in order to limit the ransomware’s reach.”

An alert published by Spain’s national computer emergency response team (CCN-CERT) suggested that the reason for the rapid spread of Wana Decryptor is that it is leveraging a software vulnerability in Windows computers that Microsoft patched in March. Continue reading →

SSA.GOV To Require Stronger Authentication

May 10, 2017

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The U.S. Social Security Administration will soon require Americans to use stronger authentication when accessing their accounts at ssa.gov. As part of the change, SSA will require all users to enter a username and password in addition to a one-time security code sent their email or phone. In this post, we’ll parse this a bit more and look at some additional security options for SSA users.

The SSA recently updated its portal with the following message:

The Social Security Administration’s message to Americans regarding the new login
changes coming in July 2017.

I read that to mean even though an email address is required to sign up at ssa.gov, the SSA also is treating email as a second authentication factor. But the above statement seemed open to interpretation, so I put my questions to the SSA: Here’s what SSA’s press office came back with:

“Beginning June 10, 2017, we will require all my Social Security account holders (both new and returning) to use a stronger authentication method to create an account or access their account. In addition to entering the username and password, people must select either of the following options to receive a one-time use security code:

A text message; or
An email.

During registration and each subsequent login, customers will receive a new, one-time use security code by text message or email – depending on their choice.

The combination of the username, password, and one-time use security code will provide access to their personal my Social Security account.”

ANALYSIS

The idea that one can reset the password using the same email account that will receive the one-time code seems to lessen the value of this requirement as a security measure.

Notice the SSA isn’t referring to its new security scheme as “two-factor authentication,” which requires the user to supply something he knows and something he is or has. Continue reading →

Emergency Fix for Windows Anti-Malware Flaw Leads May’s Patch Tuesday

May 9, 2017

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Adobe and Microsoft both issued updates today to fix critical security vulnerabilities in their software. Microsoft actually released an emergency update on Monday just hours ahead of today’s regularly scheduled “Patch Tuesday” (the 2nd Tuesday of each month) to fix a dangerous flaw present in most of Microsoft’s anti-malware technology that’s being called the worst Windows bug in recent memory. Separately, Adobe has a new version of its Flash Player software available that squashes at least seven nasty bugs.

crackedwin Last week, Google security researchers Natalie Silvanovich and Tavis Ormandy reported to Microsoft a flaw in its Malware Protection Engine, a technology that exists in most of Redmond’s malware protection offerings — including Microsoft Forefront, Microsoft Security Essentials and Windows Defender. Rather than worry about their malicious software making it past Microsoft’s anti-malware technology, attackers could simply exploit this flaw to run their malware automatically once their suspicious file is scanned.

“To exploit this vulnerability, a specially crafted file must be scanned by an affected version of the Microsoft Malware Protection Engine,” Microsoft warned. “If the affected antimalware software has real-time protection turned on, the Microsoft Malware Protection Engine will scan files automatically, leading to exploitation of the vulnerability when the specially crafted file scanned.”

On May 8, Microsoft released an out-of-band fix for the problem, demonstrating unusual swiftness in addressing a serious issue with its software.

“Still blown away at how quickly @msftsecurity responded to protect users, can’t give enough kudos.” Google’s Ormandy tweeted on Monday. “Amazing.”

In addition to the anti-malware product update, Microsoft today released fixes for dangerous security flaws in a range of products, from Internet Explorer and Edge to Windows, Microsoft Office, .NET, and of course Adobe Flash Player. Continue reading →

Website Flaw Let True Health Diagnostics Users View All Medical Records

May 8, 2017

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Over the past two weeks readers have pointed KrebsOnSecurity to no fewer than three different healthcare providers that failed to provide the most basic care to protect their patients’ records online. Only one of the three companies — the subject of today’s story — required users to be logged on in order to view all patient records.

thg A week ago I heard from Troy Mursch, an IT consultant based in Las Vegas. A big fan of proactive medical testing, Mursch said he’s been getting his various lab results reviewed annually for the past two years with the help of a company based in Frisco, Texas called True Health Diagnostics.

True Health is a privately held health services company specializing in “comprehensive testing for early detection of chronic diseases,” according to the company’s Web site.

The medical reports that True Health produces contain vast amounts of extremely personal information on patients, including indicators of genetic abnormalities as well as markers of potentially current and future diseases.

To demonstrate the flaw, Mursch logged into his account at True Health and right clicked on the PDF file for his latest health report. He showed how the site would readily cough up someone else’s detailed health records and blood tests if he modified a single digit in the link attached to that PDF record and then refreshed the page.

I alerted True Health Diagnostics immediately after verifying the flaw, and they responded by disabling the healthcare records data portal within minutes of our call. Over the weekend, True Health said it discovered and fixed the source of the problem.

“Upon discovering the potential for registered users of our patient portal to access data for individuals other than themselves, we immediately shut down the system in order to resolve any vulnerabilities,” the company said in a statement emailed to this author. “True Health has total confidence that all patient records are fully secure at this time. We regret this situation and any harm it may have caused.”

The statement said True Health CEO Chris Grottenthaler has ordered an immediate investigation to determine which files, if any, were improperly accessed.

“It will be thorough, speedy and transparent,” the statement concludes. “Nothing is more important to us than the trust that doctors and patients put in our company.”

The company says it is still investigating how long this vulnerability may have existed. But Mursch said it appears his healthcare record was assigned by True Health a record number that was issued as part of a numerical sequence, and that the difference between the record numbers attached to a result he received recently and another set of test results produced two years ago indicate at least two million records may have been exposed in between.

“I would assume all patient records were exposed,” Mursch wrote in an email.

Alex Holden, founder of cybersecurity consultancy Hold Security, said he’s responded to a number of inquiries of late regarding clients who inadvertently published patient data online with little or no authentication needed to view sensitive health records.

Holden said he advises clients to add security components to their links to encrypt any portion of the link that contains data so that it can’t be easily reversed or manipulated. He also tells clients not to use sequential account numbers that can be discovered by simply increasing or decreasing an existing account number by a single digit.

“A lot of times the medical records are stored sequentially as PDF files and they all just sit in the same folder that patients can access with a Web browser,” Holden said. “And in many cases they are not even protected by a username and password.” Continue reading →

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