Change Healthcare says it has notified approximately 100 million Americans that their personal, financial and healthcare records may have been stolen in a February 2024 ransomware attack that caused the largest ever known data breach of protected health information.

Image: Tamer Tuncay, Shutterstock.com.

A ransomware attack at Change Healthcare in the third week of February quickly spawned disruptions across the U.S. healthcare system that reverberated for months, thanks to the company’s central role in processing payments and prescriptions on behalf of thousands of organizations.

In April, Change estimated the breach would affect a “substantial proportion of people in America.” On Oct 22, the healthcare giant notified the U.S. Department of Health and Human Resources (HHS) that “approximately 100 million notices have been sent regarding this breach.”

A notification letter from Change Healthcare said the breach involved the theft of:

-Health Data: Medical record #s, doctors, diagnoses, medicines, test results, images, care and treatment;
-Billing Records: Records including payment cards, financial and banking records;
-Personal Data: Social Security number; driver’s license or state ID number;
-Insurance Data: Health plans/policies, insurance companies, member/group ID numbers, and Medicaid-Medicare-government payor ID numbers.

The HIPAA Journal reports that in the nine months ending on September 30, 2024, Change’s parent firm United Health Group had incurred $1.521 billion in direct breach response costs, and $2.457 billion in total cyberattack impacts.

Those costs include $22 million the company admitted to paying their extortionists — a ransomware group known as BlackCat and ALPHV — in exchange for a promise to destroy the stolen healthcare data.

That ransom payment went sideways when the affiliate who gave BlackCat access to Change’s network said the crime gang had cheated them out of their share of the ransom. The entire BlackCat ransomware operation shut down after that, absconding with all of the money still owed to affiliates who were hired to install their ransomware.

A breach notification from Change Healthcare.

A few days after BlackCat imploded, the same stolen healthcare data was offered for sale by a competing ransomware affiliate group called RansomHub.

“Affected insurance providers can contact us to prevent leaking of their own data and [remove it] from the sale,” RansomHub’s victim shaming blog announced on April 16. “Change Health and United Health processing of sensitive data for all of these companies is just something unbelievable. For most US individuals out there doubting us, we probably have your personal data.”

It remains unclear if RansomHub ever sold the stolen healthcare data. The chief information security officer for a large academic healthcare system affected by the breach told KrebsOnSecurity they participated in a call with the FBI and were told a third party partner managed to recover at least four terabytes of data that was exfiltrated from Change by the cybercriminal group. The FBI did not respond to a request for comment.

Change Healthcare’s breach notification letter offers recipients two years of credit monitoring and identity theft protection services from a company called IDX. In the section of the missive titled “Why did this happen?,” Change shared only that “a cybercriminal accessed our computer system without our permission.”

But in June 2024 testimony to the Senate Finance Committee, it emerged that the intruders had stolen or purchased credentials for a Citrix portal used for remote access, and that no multi-factor authentication was required for that account.

Last month, Sens. Mark Warner (D-Va.) and Ron Wyden (D-Ore.) introduced a bill that would require HHS to develop and enforce a set of tough minimum cybersecurity standards for healthcare providers, health plans, clearinghouses and businesses associates. The measure also would remove the existing cap on fines under the Health Insurance Portability and Accountability Act, which severely limits the financial penalties HHS can issue against providers.

According to the HIPAA Journal, the biggest penalty imposed to date for a HIPPA violation was the paltry $16 million fine against the insurer Anthem Inc., which suffered a data breach in 2015 affecting 78.8 million individuals. Anthem reported revenues of around $80 billion in 2015.

A post about the Change breach from RansomHub on April 8, 2024. Image: Darkbeast, ke-la.com.

There is little that victims of this breach can do about the compromise of their healthcare records. However, because the data exposed includes more than enough information for identity thieves to do their thing, it would be prudent to place a security freeze on your credit file and on that of your family members if you haven’t already.

The best mechanism for preventing identity thieves from creating new accounts in your name is to freeze your credit file with Equifax, Experian, and TransUnion. This process is now free for all Americans, and simply blocks potential creditors from viewing your credit file. Parents and guardians can now also freeze the credit files for their children or dependents.

Since very few creditors are willing to grant new lines of credit without being able to determine how risky it is to do so, freezing your credit file with the Big Three is a great way to stymie all sorts of ID theft shenanigans. Having a freeze in place does nothing to prevent you from using existing lines of credit you may already have, such as credit cards, mortgage and bank accounts. When and if you ever do need to allow access to your credit file — such as when applying for a loan or new credit card — you will need to lift or temporarily thaw the freeze in advance with one or more of the bureaus.

All three bureaus allow users to place a freeze electronically after creating an account, but all of them try to steer consumers away from enacting a freeze. Instead, the bureaus are hoping consumers will opt for their confusingly named “credit lock” services, which accomplish the same result but allow the bureaus to continue selling access to your file to select partners.

If you haven’t done so in a while, now would be an excellent time to review your credit file for any mischief or errors. By law, everyone is entitled to one free credit report every 12 months from each of the three credit reporting agencies. But the Federal Trade Commission notes that the big three bureaus have permanently extended a program enacted in 2020 that lets you check your credit report at each of the agencies once a week for free.

Twice in the past month KrebsOnSecurity has heard from readers who’ve had their accounts at big-three credit bureau Experian hacked and updated with a new email address that wasn’t theirs. In both cases the readers used password managers to select strong, unique passwords for their Experian accounts. Research suggests identity thieves were able to hijack the accounts simply by signing up for new accounts at Experian using the victim’s personal information and a different email address.

John Turner is a software engineer based in Salt Lake City. Turner said he created the account at Experian in 2020 to place a security freeze on his credit file, and that he used a password manager to select and store a strong, unique password for his Experian account.

Turner said that in early June 2022 he received an email from Experian saying the email address on his account had been changed. Experian’s password reset process was useless at that point because any password reset links would be sent to the new (impostor’s) email address.

An Experian support person Turner reached via phone after a lengthy hold time asked for his Social Security Number (SSN) and date of birth, as well as his account PIN and answers to his secret questions. But the PIN and secret questions had already been changed by whoever re-signed up as him at Experian.

“I was able to answer the credit report questions successfully, which authenticated me to their system,” Turner said. “At that point, the representative read me the current stored security questions and PIN, and they were definitely not things I would have used.”

Turner said he was able to regain control over his Experian account by creating a new account. But now he’s wondering what else he could do to prevent another account compromise. That’s because Experian does not offer any type of multi-factor authentication options on consumer accounts.

“The most frustrating part of this whole thing is that I received multiple ‘here’s your login information’ emails later that I attributed to the original attackers coming back and attempting to use the ‘forgot email/username’ flow, likely using my SSN and DOB, but it didn’t go to their email that they were expecting,” Turner said. “Given that Experian doesn’t support two-factor authentication of any kind — and that I don’t know how they were able to get access to my account in the first place — I’ve felt very helpless ever since.”

To be clear, Experian does have a business unit that sells one-time password services to businesses. But it does not offer this directly to consumers who sign up to manage their credit file at Experian’s website.

Arthur Rishi is a musician and co-executive director of the Boston Landmarks Orchestra. Rishi said he recently discovered his Experian account had been hijacked after receiving an alert from his credit monitoring service (not Experian’s) that someone had tried to open an account in his name at JPMorgan Chase.

Rishi said the alert surprised him because his credit file at Experian was frozen at the time, and Experian did not notify him about any activity on his account. Rishi said Chase agreed to cancel the unauthorized account application, and even rescinded its credit inquiry (each credit pull can ding your credit score slightly).

But he never could get anyone from Experian’s support to answer the phone, despite spending what seemed like eternity trying to progress through the company’s phone-based system. That’s when Rishi decided to see if he could create a new account for himself at Experian.

“I was able to open a new account at Experian starting from scratch, using my SSN, date of birth and answering some really basic questions, like what kind of car did you take out a loan for, or what city did you used to live in,’ Rishi said.

Upon completing the sign-up, Rishi noticed that his credit was unfrozen.

Like Turner, Rishi is now worried that identity thieves will just hijack his Experian account once more, and that there is nothing he can do to prevent such a scenario. For now, Rishi has decided to pay Experian $25.99 a month to more closely monitor his account for suspicious activity. Even using the paid Experian service, there were no additional multi-factor authentication options available, although he said Experian did send a one-time code to his phone via SMS recently when he logged on.

“Experian now sometimes does require MFA for me now if I use a new browser or have my VPN on,” Rishi said, but he’s not sure if Experian’s free service would have operated differently.

“I get so angry when I think about all this,” he said. “I have no confidence this won’t happen again.”

In a written statement, Experian suggested that what happened to Rishi and Turner was not a normal occurrence, and that its security and identity verification practices extend beyond what is visible to the user.

“We believe these are isolated incidents of fraud using stolen consumer information,” Experian’s statement reads. “Specific to your question, once an Experian account is created, if someone attempts to create a second Experian account, our systems will notify the original email on file.”

“We go beyond reliance on personally identifiable information (PII) or a consumer’s ability to answer knowledge-based authentication questions to access our systems,” the statement continues. “We do not disclose additional processes for obvious security reasons; however, our data and analytical capabilities verify identity elements across multiple data sources and are not visible to the consumer. This is designed to create a more positive experience for our consumers and to provide additional layers of protection. We take consumer privacy and security seriously, and we continually review our security processes to guard against constant and evolving threats posed by fraudsters.”

ANALYSIS

KrebsOnSecurity sought to replicate Turner and Rishi’s experience — to see if Experian would allow me to re-create my account using my personal information but a different email address. The experiment was done from a different computer and Internet address than the one that created the original account years ago.

After providing my Social Security Number (SSN), date of birth, and answering several multiple choice questions whose answers are derived almost entirely from public records, Experian promptly changed the email address associated with my credit file. It did so without first confirming that new email address could respond to messages, or that the previous email address approved the change.

Experian’s system then sent an automated message to the original email address on file, saying the account’s email address had been changed. The only recourse Experian offered in the alert was to sign in, or send an email to an Experian inbox that replies with the message, “this email address is no longer monitored.”

After that, Experian prompted me to select new secret questions and answers, as well as a new account PIN — effectively erasing the account’s previously chosen PIN and recovery questions. Once I’d changed the PIN and security questions, Experian’s site helpfully reminded me that I have a security freeze on file, and would I like to remove or temporarily lift the security freeze?

How does Experian differ from the practices of Equifax and TransUnion, the other two big consumer credit reporting bureaus? When KrebsOnSecurity tried to re-create an existing account at TransUnion using my Social Security number, TransUnion rejected the application, noting that I already had an account and prompting me to proceed through its lost password flow. The company also appears to send an email to the address on file asking to validate account changes.

Likewise, trying to recreate an existing account at Equifax using personal information tied to my existing account prompts Equifax’s systems to report that I already have an account, and to use their password reset process (which involves sending a verification email to the address on file).

KrebsOnSecurity has long urged readers in the United States to place a security freeze on their files with the three major credit bureaus. With a freeze in place, potential creditors can’t pull your credit file, which makes it very unlikely anyone will be granted new lines of credit in your name. I’ve also advised readers to plant their flag at the three major bureaus, to prevent identity thieves from creating an account for you and assuming control over your identity.

The experiences of Rishi, Turner and this author suggest Experian’s practices currently undermine both of those proactive security measures. Even so, having an active account at Experian may be the only way you find out when crooks have assumed your identity. Because at least then you should receive an email from Experian saying they gave your identity to someone else.

In April 2021, KrebsOnSecurity revealed how identity thieves were exploiting lax authentication on Experian’s PIN retrieval page to unfreeze consumer credit files. In those cases, Experian failed to send any notice via email when a freeze PIN was retrieved, nor did it require the PIN to be sent to an email address already associated with the consumer’s account.

A few days after that April 2021 story, KrebsOnSecurity broke the news that an Experian API was exposing the credit scores of most Americans.

Emory Roan, policy counsel for the Privacy Rights Clearinghouse, said Experian not offering multi-factor authentication for consumer accounts is inexcusable in 2022.

“They compound the problem by gating the recovery process with information that’s likely available or inferable from third party data brokers, or that could have been exposed in previous data breaches,” Roan said. “Experian is one of the largest Consumer Reporting Agencies in the country, trusted as one of the few essential players in a credit system Americans are forced to be part of. For them to not offer consumers some form of (free) MFA is baffling and reflects extremely poorly on Experian.”

Nicholas Weaver, a researcher for the International Computer Science Institute at University of California, Berkeley, said Experian has no real incentive to do things right on the consumer side of its business. That is, he said, unless Experian’s customers — banks and other lenders — choose to vote with their feet because too many people with frozen credit files are having to deal with unauthorized applications for new credit.

“The actual customers of the credit service don’t realize how much worse Experian is, and this isn’t the first time Experian has screwed up horribly,” Weaver said. “Experian is part of a triopoly, and I’m sure this is costing their actual customers money, because if you have a credit freeze that gets lifted and somebody loans against it, it’s the lender who eats that fraud cost.”

And unlike consumers, he said, lenders do have a choice in which of the triopoly handles their credit checks.

“I do think it’s important to point out that their real customers do have a choice, and they should switch to TransUnion and Equifax,” he added.

More greatest hits from Experian:

2017: Experian Site Can Give Anyone Your Credit Freeze PIN
2015: Experian Breach Affects 15 Million Customers
2015: Experian Breach Tied to NY-NJ ID Theft Ring
2015: At Experian, Security Attrition Amid Acquisitions
2015: Experian Hit With Class Action Over ID Theft Service
2014: Experian Lapse Allowed ID Theft Service Access to 200 Million Consumer Records
2013: Experian Sold Consumer Data to ID Theft Service