28
Apr 20

Would You Have Fallen for This Phone Scam?

You may have heard that today’s phone fraudsters like to use caller ID spoofing services to make their scam calls seem more believable. But you probably didn’t know that these fraudsters also can use caller ID spoofing to trick your bank into giving up information about recent transactions on your account — data that can then be abused to make their phone scams more believable and expose you to additional forms of identity theft.

Last week, KrebsOnSecurity told the harrowing tale of a reader (a security expert, no less) who tried to turn the tables on his telephonic tormentors and failed spectacularly. In that episode, the people impersonating his bank not only spoofed the bank’s real phone number, but they were also pretending to be him on a separate call at the same time with his bank.

This foiled his efforts to make sure it was really his bank that called him, because he called his bank with another phone and the bank confirmed they currently were in a separate call with him discussing fraud on his account (however, the other call was the fraudster pretending to be him).

Shortly after that story ran, I heard from another reader — we’ll call him “Jim” since he didn’t want his real name used for this story — whose wife was the target of a similar scam, albeit with an important twist: The scammers were armed with information about a number of her recent financial transactions, which he claims they got from the bank’s own automated phone system just by spoofing her phone number.

“When they originally called my wife, there were no fraudulent transactions on her account, but they were able to specify the last three transactions she had made, which combined with the caller-ID had mistakenly earned her trust,” Jim explained. “After we figured out what was going on, we were left asking ourselves how the crooks had obtained her last three transactions without breaking into her account online. As it turned out, calling the phone number on the back of the credit card from the phone number linked with the card provided the most recent transactions without providing any form of authentication.”

Jim said he was so aghast at this realization that he called the same number from his phone and tried accessing his account, which is also at Citi but wholly separate from his spouse’s. Sure enough, he said, as long as he was calling from the number on file for his account, the automated system let him review recent transactions without any further authentication.

“I confirmed on my separate Citi card that they often (but not quite always) were providing the transaction details,” Jim said. “I was appalled that Citi would do that. So, it seemed the crooks would spoof caller ID when calling Citibank, as well as when calling the target/victim.

The incident Jim described happened in late January 2020, and Citi may have changed its procedures since then. But in a phone interview with KrebsOnSecurity earlier this week, Jim made a call to Citi’s automated system from his mobile phone on file with the bank, and I could hear Citi’s systems asking him to enter the last four digits of his credit card number before he could review recent transactions.

The request for the last four of the customer’s credit card number was consistent with my own testing, which relied on a caller ID spoofing service advertised in the cybercrime underground and aimed at a Citi account controlled by this author.

In one test, the spoofed call let KrebsOnSecurity hear recent transaction data — where and when the transaction was made, and how much was spent — after providing the automated system the last four digits of the account’s credit card number. In another test, the automated system asked for the account holder’s full Social Security number.

Citi declined to discuss specific actions it takes to detect and prevent fraud. But in a written statement provided to this author it said the company continuously monitors and analyzes threats and looks for opportunities to strengthen its controls.

“We see regular attempts by fraudsters to gain access to information and we are constantly monitoring for emerging threats and taking preventive action for our clients’ protection,” the statement reads. “For inbound calls to call centers, we continue to adapt and implement detection capabilities to identify suspicious or spoofed phone numbers. We also encourage clients to install and use our mobile app and sign up for push notifications and alerts in the mobile app.”

PREGNANT PAUSES AND BULGING EMAIL BOMBS

Jim said the fraudster who called his wife clearly already knew her mailing and email addresses, her mobile number and the fact that her card was an American Airlines-branded Citi card. The caller said there had been a series of suspicious transactions, and proceeded to read back details of several recent transactions to verify if those were purchases she’d authorized.

A list of services offered by one of several underground stores that sell caller ID spoofing and email bombing services.

Jim’s wife quickly logged on to her Citi account and saw that the amounts, dates and places of the transactions referenced by the caller indeed corresponded to recent legitimate transactions. But she didn’t see any signs of unauthorized charges.

After verifying the recent legitimate transactions with the caller, the person on the phone asked for her security word. When she provided it, there was a long hold before the caller came back and said she’d provided the wrong answer.

When she corrected herself and provided a different security word, there was another long pause before the caller said the second answer she provided was correct. At that point, the caller said Citi would be sending her a new card and that it had prevented several phony charges from even posting to her account.

She didn’t understand until later that the pauses were points at which the fraudsters had to put her on hold to relay her answers in their own call posing as her to Citi’s customer service department.

Not long after Jim’s spouse hung up with the caller, her inbox quickly began filling up with hundreds of automated messages from various websites trying to confirm an email newsletter subscription she’d supposedly requested.

As the recipient of several of theseemail bombing” attacks, I can verify that crooks often will use services offered in the cybercrime underground to flood a target’s inbox with these junk newsletter subscriptions shortly after committing fraud in the target’s name when they wish to bury an email notification from a target’s bank.

‘OVERPAYMENT REIMBURSEMENT’

In the case of Jim’s wife, the inbox flood backfired, and only made her more suspicious about the true nature of the recent phone call. So she called the number on the back of her Citi card and was told that she had indeed just called Citi and requested what’s known as an “overpayment reimbursement.” The couple have long had their credit cards on auto-payment, and the most recent payment was especially high — nearly $4,000 — thanks to a flurry of Christmas present purchases for friends and family.

In an overpayment reimbursement, a customer can request that the bank refund any amount paid toward a previous bill that exceeds the minimum required monthly payment. Doing so causes any back-due interest on that unpaid amount to accrue to the account as well.

In this case, the caller posing as Jim’s wife requested an overpayment reimbursement to the tune of just under $4,000. It’s not clear how or where the fraudsters intended this payment to be sent, but for whatever reason Citi ended up saying they would cut a physical check and mail it to the address on file. Probably not what the fraudsters wanted, although since then Jim and his wife say they have been on alert for anyone suspicious lurking near their mailbox.

“The person we spoke with at Citi’s fraud department kept insisting that yes, it was my wife that called because the call came from her mobile number,” Jim said. “The Citi employee was alarmed because she didn’t understand the whole notion of caller ID spoofing. And we both found it kind of disturbing that someone in fraud at such a major bank didn’t even understand that such a thing was possible.” Continue reading →


24
Apr 20

Unproven Coronavirus Therapy Proves Cash Cow for Shadow Pharmacies

Many of the same shadowy organizations that pay people to promote male erectile dysfunction drugs via spam and hacked websites recently have enjoyed a surge in demand for medicines used to fight malaria, lupus and arthritis, thanks largely to unfounded suggestions that these therapies can help combat the COVID-19 pandemic.

A review of the sales figures from some of the top pharmacy affiliate programs suggests sales of drugs containing hydroxychloroquine rivaled that of their primary product — generic Viagra and Cialis — and that this as-yet-unproven Coronavirus treatment accounted for as much as 25 to 30 percent of all sales over the past month.

A Google Trends graph depicting the incidence of Web searches for “chloroquine” over the past 90 days.

KrebsOnSecurity reviewed a number of the most popular online pharmacy enterprises, in part by turning to some of the same accounts at these invite-only affiliate programs I relied upon for researching my 2014 book, Spam Nation: The Inside Story of Organized Cybercrime, from Global Epidemic to Your Front Door.

Many of these affiliate programs — going by names such as EvaPharmacy, Rx-Partners and Mailien/Alientarget — have been around for more than a decade, and were major, early catalysts for the creation of large-scale botnets and malicious software designed to enslave computers for the sending of junk email.

Their products do not require a prescription, are largely sourced directly from pharmaceutical production facilities in India and China, and are shipped via international parcel post to customers around the world.

In mid-March, two influential figures — President Trump and Tesla CEO Elon Muskbegan suggesting that hydroxychloroquine should be more strongly considered as a treatment for COVID-19.

The pharmacy affiliate programs immediately took notice of a major moneymaking opportunity, noting that keyword searches for terms related to chloroquine suddenly were many times more popular than for the other mainstays of their business.

“Everyone is hysterical,” wrote one member of the Russian language affiliate forum gofuckbiz[.]com on Mar. 17. “Time to make extra money. Do any [pharmacy affiliate] programs sell drugs for Coronavirus or flu?”

The larger affiliate programs quickly pounced on the opportunity, which turned out to be a major — albeit short-lived — moneymaker. Below is a screenshot of the overall product sales statistics for the previous 30 days from all affiliates of PharmCash. As we can see, Aralen — a chloroquine drug used to treat and prevent malaria — was the third biggest seller behind Viagra and Cialis.

Recent 30-day sales figures from the pharmacy affiliate program PharmCash.

In mid-March, the affiliate program Rx-Partners saw a huge spike in demand for Aralen and other drugs containing chloroquine phosphate, and began encouraging affiliates to promote a new set of product teasers targeting people anxiously seeking remedies for COVID-19.

Their main promotion page — still online at about-coronavirus2019[.]com — touts the potential of Aralen, generic hydroxychloroquine, and generic Kaletra/Lopinavir, a drug used to treat HIV/AIDS.

An ad promoting various unproven remedies for COVID-19, from the pharmacy affiliate program Rx-Partners.

On Mar. 18, a manager for Rx-Partners said that like PharmCash, drugs which included chloroquine phosphate had already risen to the top of sales for non-erectile dysfunction drugs across the program. Continue reading →


23
Apr 20

When in Doubt: Hang Up, Look Up, & Call Back

Many security-conscious people probably think they’d never fall for a phone-based phishing scam. But if your response to such a scam involves anything other than hanging up and calling back the entity that claims to be calling, you may be in for a rude awakening. Here’s how one security and tech-savvy reader got taken for more than $10,000 in an elaborate, weeks-long ruse.

Today’s lesson in how not to get scammed comes from “Mitch,” the pseudonym I picked for a reader in California who shared his harrowing tale on condition of anonymity. Mitch is a veteran of the tech industry — having worked in security for several years at a fairly major cloud-based service — so he’s understandably embarrassed that he got taken in by this confidence scheme.

On Friday, April 17, Mitch received a call from what he thought was his financial institution, warning him that fraud had been detected on his account. Mitch said the caller ID for that incoming call displayed the same phone number that was printed on the back of his debit card.

But Mitch knew enough of scams to understand that fraudsters can and often do spoof phone numbers. So while still on the phone with the caller, he quickly logged into his account and saw that there were indeed multiple unauthorized transactions going back several weeks. Most were relatively small charges — under $100 apiece — but there were also two very recent $800 ATM withdrawals from cash machines in Florida.

If the caller had been a fraudster, he reasoned at the time, they would have asked for personal information. But the nice lady on the phone didn’t ask Mitch for any personal details. Instead, she calmly assured him the bank would reverse the fraudulent charges and said they’d be sending him a new debit card via express mail. After making sure the representative knew which transactions were not his, Mitch thanked the woman for notifying him, and hung up.

The following day, Mitch received another call about suspected fraud on his bank account. Something about that conversation didn’t seem right, and so Mitch decided to use another phone to place a call to his bank’s customer service department — while keeping the first caller on hold.

“When the representative finally answered my call, I asked them to confirm that I was on the phone with them on the other line in the call they initiated toward me, and so the rep somehow checked and saw that there was another active call with Mitch,” he said. “But as it turned out, that other call was the attackers also talking to my bank pretending to be me.”

Mitch said his financial institution has in the past verified his identity over the phone by sending him a one-time code to the cell phone number on file for his account, and then asking him to read back that code. After he hung up with the customer service rep he’d phoned, the person on the original call said the bank would be sending him a one-time code to validate his identity.

Now confident he was speaking with a representative from his bank and not some fraudster, Mitch read back the code that appeared via text message shortly thereafter. After more assurances that any additional phony charges would be credited to his account and that he’d be receiving a new card soon, Mitch was annoyed but otherwise satisfied. He said he checked his account online several times over the weekend, but saw no further signs of unauthorized activity.

That is, until the following Monday, when Mitch once again logged in and saw that a $9,800 outgoing wire transfer had been posted to his account. At that point, it dawned on Mitch that both the Friday and Saturday calls he received had likely been from scammers — not from his bank.

Another call to his financial institution and some escalation to its fraud department confirmed that suspicion: The investigator said another man had called in on Saturday posing as Mitch, had provided a one-time code the bank texted to the phone number on file for Mitch’s account — the same code the real Mitch had been tricked into giving up — and then initiated an outgoing wire transfer.

It appears the initial call on Friday was to make him think his bank was aware of and responding to active fraud against his account, when in actuality the bank was not at that time. Also, the Friday call helped to set up the bigger heist the following day.

Mitch said he and his bank now believe that at some point his debit card and PIN were stolen, most likely by a skimming device planted at a compromised point-of-sale terminal, gas pump or ATM he’d used in the past few weeks. Armed with a counterfeit copy of his debit card and PIN, the fraudsters could pull money out of his account at ATMs and go shopping in big box stores for various items. But to move lots of money out of his account all at once, they needed Mitch’s help. Continue reading →


20
Apr 20

Who’s Behind the “Reopen” Domain Surge?

The past few weeks have seen a large number of new domain registrations beginning with the word “reopen” and ending with U.S. city or state names. The largest number of them were created just hours after President Trump sent a series of all-caps tweets urging citizens to “liberate” themselves from new gun control measures and state leaders who’ve enacted strict social distancing restrictions in the face of the COVID-19 pandemic. Here’s a closer look at who and what appear to be behind these domains.

A series of inciteful tweets sent by President Trump on April 17, the same day dozens of state-themed “reopen” domains were registered — mostly by conservative groups and gun rights advocates.

KrebsOnSecurity began this research after reading a fascinating Reddit thread over the weekend on several “reopen” sites that seemed to be engaged in astroturfing, which involves masking the sponsors of a message or organization to make it appear as though it originates from and is supported by grassroots participants.

The Reddit discussion focused on a handful of new domains — including reopenmn.com, reopenpa.com, and reopenva.com — that appeared to be tied to various gun rights groups in those states. Their registrations have roughly coincided with contemporaneous demonstrations in Minnesota, California and Tennessee where people showed up to protest quarantine restrictions over the past few days.

A “reopen California” protest over the weekend in Huntington Beach, Calif. Image: Reddit.

Suspecting that these were but a subset of a larger corpus of similar domains registered for every state in the union, KrebsOnSecurity ran a domain search report at DomainTools [an advertiser on this site], requesting any and all domains registered in the past month that begin with “reopen” and end in “.com.”

That lookup returned approximately 150 domains; in addition to those named after the individual 50 states, some of the domains refer to large American cities or counties, and others to more general concepts, such as “reopeningchurch.com” or “reopenamericanbusiness.com.”

Many of the domains are still dormant, leading to parked pages and registration records obscured behind privacy protection services. But a review of other details about these domains suggests a majority of them are tied to various gun rights groups, state Republican Party organizations, and conservative think tanks, religious and advocacy groups.

For example, reopenmn.com forwards to minnesotagunrights.org, but the site’s WHOIS registration records (obscured since the Reddit thread went viral) point to an individual living in Florida. That same Florida resident registered reopenpa.com, a site that forwards to the Pennsylvania Firearms Association, and urges the state’s residents to contact their governor about easing the COVID-19 restrictions.

Reopenpa.com is tied to a Facebook page called Pennsylvanians Against Excessive Quarantine, which sought to organize an “Operation Gridlock” protest at noon today in Pennsylvania among its 68,000 members.

Both the Minnesota and Pennsylvania gun advocacy sites include the same Google Analytics tracker in their source code: UA-60996284. A cursory Internet search on that code shows it also is present on reopentexasnow.comreopenwi.com and reopeniowa.com.

More importantly, the same code shows up on a number of other anti-gun control sites registered by the Dorr Brothers, real-life brothers who have created nonprofits (in name only) across dozens of states that are so extreme in their stance they make the National Rifle Association look like a liberal group by comparison.

This 2019 article at cleveland.com quotes several 2nd Amendment advocates saying the Dorr brothers simply seek “to stir the pot and make as much animosity as they can, and then raise money off that animosity.” The site dorrbrotherscams.com also is instructive here.

A number of other sites — such as reopennc.com — seem to exist merely to sell t-shirts, decals and yard signs with such slogans as “Know Your Rights,” “Live Free or Die,” and “Facts not Fear.” WHOIS records show the same Florida resident who registered this North Carolina site also registered one for New York — reopenny.com — just a few minutes later.

Merchandise available from reopennc.com.

Some of the concept reopen domains — including reopenoureconomy.com (registered Apr. 15) and reopensociety.com (Apr. 16) — trace back to FreedomWorks, a conservative group that the Associated Press says has been holding weekly virtual town halls with members of Congress, “igniting an activist base of thousands of supporters across the nation to back up the effort.”

Reopenoc.com — which advocates for lifting social restrictions in Orange County, Calif. — links to a Facebook page for Orange County Republicans, and has been chronicling the street protests there. The messaging on Reopensc.com — urging visitors to digitally sign a reopen petition to the state governor — is identical to the message on the Facebook page of the Horry County, SC Conservative Republicans.

Reopenmississippi.com was registered on April 16 to In Pursuit of LLC, an Arlington, Va.-based conservative group with a number of former employees who currently work at the White House or in cabinet agencies. A 2016 story from USA Today says In Pursuit Of LLC is a for-profit communications agency launched by billionaire industrialist Charles Koch. Continue reading →


16
Apr 20

Sipping from the Coronavirus Domain Firehose

Security experts are poring over thousands of new Coronavirus-themed domain names registered each day, but this often manual effort struggles to keep pace with the flood of domains invoking the virus to promote malware and phishing sites, as well as non-existent healthcare products and charities. As a result, domain name registrars are under increasing pressure to do more to combat scams and misinformation during the COVID-19 pandemic.

By most measures, the volume of new domain registrations that include the words “Coronavirus” or “Covid” has closely tracked the spread of the deadly virus. The Cyber Threat Coalition (CTC), a group of several thousand security experts volunteering their time to fight COVID-related criminal activity online, recently published data showing the rapid rise in new domains began in the last week of February, around the same time the Centers for Disease Control began publicly warning that a severe global pandemic was probably inevitable.

The total number of domains registered per day that contain a COVID-19 related term, according to DomainTools. The red line indicates the count of domains that DomainTools determined are “likely malicious.” The blue line refers to domains that are likely benign.

“Since March 20th, the number of risky domains registered per day has been decreasing, with a notable spike around March 30th,” wrote John Conwell, principal data scientist at DomainTools [an advertiser on this site]. “Interestingly, legitimate organizations creating domains in response to the COVID-19 crisis were several weeks behind the curve from threat actors trying to take advantage of this situation. This is a pattern DomainTools hasn’t seen before in other crises.”

Security vendor Sophos looked at telemetry from customer endpoints to illustrate the number of new COVID-related domains that actually received traffic of late. As the company noted, one challenge in identifying potentially malicious domains is that many of them can sit dormant for days or weeks before being used for anything.

Data from security vendor Sophos, published by the Cyber Threat Coalition, shows the number of Coronavirus or COVID-19 themed domains registered per week that received traffic.

“We can see a rapid and dramatic increase of visits to potentially malicious domains exploiting the Coronavirus pandemic week over week, beginning in late February,” wrote Sophos’ Rich Harang. “Even though still a minority of cyber threats use the pandemic as a lure, some of these new domains will eventually be used for malicious purposes.”

CTC spokesman Nick Espinosa said the first spike in visits was on February 25, when group members saw about 4,000 visits to the sites they were tracking.

“The following two weeks starting on March 9 saw rapid growth, and from March 23 onwards we’re seeing between 75,000 to 130,000 visits per weekday, and about 40,000 on the weekends,” Espinosa said. “Looking at the data collected, the pattern of visits are highest on Monday and Friday, and the lowest visit count is on the weekend. Our data shows that there were virtually no customer hits on COVID-related domains prior to February 23.”

Milwaukee-based Hold Security has been publishing daily and weekly lists of all COVID-19 related domain registrations (without any scoring assigned). Here’s a graph KrebsOnSecurity put together based on that data set, which also shows a massive spike in new domain registrations in the third week of March, trailing off considerably over the past couple of weeks.

Data: Hold Security.

Not everyone is convinced we’re measuring the right things, or that the current measurements are accurate. Neil Schwartzman, executive director of the anti-spam group CAUCE, said he believes DomainTool’s estimates on the percentage of new COVID/Coronavirus-themed domains that are malicious are too high, and that many are likely benign and registered by well-meaning people seeking to share news or their own thoughts about the outbreak.

“But there’s the rub,” he said. “Bad guys get to hide amidst the good really effectively, so each one needs to be reviewed on its own. And that’s a substantial amount of work.” Continue reading →


15
Apr 20

COVID-19 Has United Cybersecurity Experts, But Will That Unity Survive the Pandemic?

The Coronavirus has prompted thousands of information security professionals to volunteer their skills in upstart collaborative efforts aimed at frustrating cybercriminals who are seeking to exploit the crisis for financial gain. Whether it’s helping hospitals avoid becoming the next ransomware victim or kneecapping new COVID-19-themed scam websites, these nascent partnerships may well end up saving lives. But can this unprecedented level of collaboration survive the pandemic?

At least three major industry groups are working to counter the latest cyber threats and scams. Among the largest in terms of contributors is the COVID-19 Cyber Threat Coalition (CTC), which comprises rough 3,000 security professionals who are collecting, vetting and sharing new intelligence about new cyber threats.

Nick Espinosa, a self-described “security fanatic,” author and public speaker who’s handling communications for the CTC, said the group does most of its work remotely via a dedicated Slack channel, where many infosec professionals seem eager to counter the gusto with which the cybercriminal community has sought to profit by exacerbating an already difficult situation.

“A nurse or doctor can’t do what we do, and we can’t do what they do,” Espinosa said. “We’ve seen a massive rise in threats and attacks against healthcare systems, but it’s worse if someone dies due to a malicious cyberattack when we have the ability to prevent that. A lot of people are involved because they’re emotionally attached to the idea of helping this critical infrastructure stay safe and online.”

Using threat intelligence feeds donated by dozens of cybersecurity companies, the CTC is poring over more than 100 million pieces of data about potential threats each day, running those indicators through security products from roughly 70 different vendors. If at least 10 of those flag a specific data point — such as a domain name — as malicious or bad, it gets added to the CTC’s blocklist, which is designed to be used by organizations worldwide for blocking malicious traffic.

“For possible threats, meaning between five and nine vendors detect an indicator as bad, our volunteers manually verify that the indicator is malicious before including it in our blocklist,” Espinosa said.

Another Slack-based upstart coalition called the COVID-19 CTI League spans more than 40 countries and includes professionals in senior positions at such major companies as Microsoft Corp and Amazon.com Inc.

Mark Rogers, one of several people helping to manage the CTI League’s efforts, told Reuters the top priority of the group is working to combat hacks against medical facilities and other frontline responders to the pandemic, as well as helping defend communication networks and services that have become essential as more people work from home.

“The group is also using its web of contacts in internet infrastructure providers to squash garden-variety phishing attacks and another financial crime that is using the fear of COVID-19 or the desire for information on it to trick regular internet users,” wrote Reuters’ Joe Menn.

“I’ve never seen this volume of phishing,” Rogers told Reuters. “I am literally seeing phishing messages in every language known to man.” Continue reading →


14
Apr 20

Microsoft Patch Tuesday, April 2020 Edition

Microsoft today released updates to fix 113 security vulnerabilities in its various Windows operating systems and related software. Those include at least three flaws that are actively being exploited, as well as two others which were publicly detailed prior to today, potentially giving attackers a head start in figuring out how to exploit the bugs.

Nineteen of the weaknesses fixed on this Patch Tuesday were assigned Microsoft’s most-dire “critical” rating, meaning malware or miscreants could exploit them to gain complete, remote control over vulnerable computers without any help from users.

Near the top of the heap is CVE-2020-1020, a remotely exploitable bug in the Adobe Font Manager library that was first detailed in late March when Microsoft said it had seen the flaw being used in active attacks.

The Adobe Font Manager library is the source of yet another zero-day flaw — CVE-2020-0938 — although experts at security vendor Tenable say there is currently no confirmation that the two are related to the same set of in-the-wild attacks. Both flaws could be exploited by getting a Windows users to open a booby-trapped document or viewing one in the Windows Preview Pane.

The other zero-day flaw (CVE-2020-1027) affects Windows 7 and Windows 10 systems, and earned a slightly less dire “important” rating from Microsoft because it’s an “elevation of privilege” bug that requires the attacker to be locally authenticated.

Many security news sites are reporting that Microsoft addressed a total of four zero-day flaws this month, but it appears the advisory for a critical Internet Explorer flaw (CVE-2020-0968) has been revised to indicate Microsoft has not yet received reports of it being used in active attacks. However, the advisory says this IE bug is likely to be exploited soon.

Researchers at security firm Recorded Future zeroed in on CVE-2020-0796, a critical vulnerability dubbed “SMBGhost” that was rumored to exist in last month’s Patch Tuesday but for which an out-of-band patch wasn’t released until March 12. The problem resides in a file-sharing component of Windows, and could be exploited merely by sending the victim machine specially-crafted data packets. Proof-of-concept code showing how to exploit the bug was released April 1, but so far there are no indications this method has been incorporated into malware or active attacks.

Recorded Future’s Allan Liska notes that one reason these past few months have seen so many patches from Microsoft is the company recently hired “SandboxEscaper,” a nickname used by the security researcher responsible for releasing more than a half-dozen zero-day flaws against Microsoft products last year.

“SandboxEscaper has made several contributions to this month’s Patch Tuesday,” Liska said. “This is great news for Microsoft and the security community at large.” Continue reading →


10
Apr 20

New IRS Site Could Make it Easy for Thieves to Intercept Some Stimulus Payments

The U.S. federal government is now in the process of sending Economic Impact Payments by direct deposit to millions of Americans. Most who are eligible for payments can expect to have funds direct-deposited into the same bank accounts listed on previous years’ tax filings sometime next week. Today, the Internal Revenue Service (IRS) stood up a site to collect bank account information from the many Americans who don’t usually file a tax return. The question is, will those non-filers have a chance to claim their payments before fraudsters do?

The IRS says the Economic Impact Payment will be $1,200 for individual or head of household filers, and $2,400 for married filing jointly if they are not a dependent of another taxpayer and have a work eligible Social Security number with adjusted gross income up to:

  • $75,000 for individuals
  • $112,500 for head of household filers and
  • $150,000 for married couples filing joint returns

Taxpayers with higher incomes will receive more modest payments (reduced by $5 for each $100 above the $75,000/$112,500/$150,000 thresholds). Most people who who filed a tax return in 2018 and/or 2019 and provided their bank account information for a debit or credit should soon see an Economic Impact Payment direct-deposited into their bank accounts. Likewise, people drawing Social Security payments from the government will receive stimulus payments the same way.

But there are millions of U.S. residents — including low-income workers and certain veterans and individuals with disabilities — who aren’t required to file a tax return but who are still eligible to receive at least a $1,200 stimulus payment. And earlier today, the IRS unveiled a Web site where it is asking those non-filers to provide their bank account information for direct deposits.

However, the possibility that fraudsters may intercept payments to these individuals seems very real, given the relatively lax identification requirements of this non-filer portal and the high incidence of tax refund fraud in years past. Each year, scam artists file phony tax refund requests on millions of Americans, regardless of whether or not the impersonated taxpayer is actually due a refund. In most cases, the victim only finds out when he or she goes to file their taxes and has the return rejected because it has already been filed by scammers.

In this case, fraudsters would simply need to identify the personal information for a pool of Americans who don’t normally file tax returns, which may well include a large number of people who are disabled, poor or simply do not have easy access to a computer or the Internet. Armed with this information, the scammers need only provide the target’s name, address, date of birth and Social Security number, and then supply their own bank account information to claim at least $1,200 in electronic payments.

Page 1 of 2 in the IRS stimulus payment application page for non-filers.

Unfortunately, SSN and DOB data is not secret, nor is it hard to come by. As noted in countless stories here, there are multiple shops in the cybercrime underground that sell SSN and DOB data on tens of millions of Americans for a few dollars per record.

A review of the Web site set up to accept bank account information for the stimulus payments reveals few other mandatory identity checks to complete the filing process. It appears that all applicants need to provide a mobile phone number and verify they can receive text messages at that number, but beyond that the rest of the identity checks seem to be optional. Continue reading →


07
Apr 20

Microsoft Buys Corp.com So Bad Guys Can’t

In February, KrebsOnSecurity told the story of a private citizen auctioning off the dangerous domain corp.com for the starting price of $1.7 million. Domain experts called corp.com dangerous because years of testing showed whoever wields it would have access to an unending stream of passwords, email and other sensitive data from hundreds of thousands of Microsoft Windows PCs at major companies around the globe. This week, Microsoft Corp. agreed to buy the domain in a bid to keep it out of the hands of those who might abuse its awesome power.

Wisconsin native Mike O’Connor, who bought corp.com 26 years ago but has done very little with it since, said he hoped Microsoft would buy it because hundreds of thousands of confused Windows PCs are constantly trying to share sensitive data with corp.com. Also, early versions of Windows actually encouraged the adoption of insecure settings that made it more likely Windows computers might try to share sensitive data with corp.com.

From February’s piece:

At issue is a problem known as “namespace collision,” a situation where domain names intended to be used exclusively on an internal company network end up overlapping with domains that can resolve normally on the open Internet.

Windows computers on an internal corporate network validate other things on that network using a Microsoft innovation called Active Directory, which is the umbrella term for a broad range of identity-related services in Windows environments. A core part of the way these things find each other involves a Windows feature called “DNS name devolution,” which is a kind of network shorthand that makes it easier to find other computers or servers without having to specify a full, legitimate domain name for those resources.

For instance, if a company runs an internal network with the name internalnetwork.example.com, and an employee on that network wishes to access a shared drive called “drive1,” there’s no need to type “drive1.internalnetwork.example.com” into Windows Explorer; typing “\\drive1\” alone will suffice, and Windows takes care of the rest.

But things can get far trickier with an internal Windows domain that does not map back to a second-level domain the organization actually owns and controls. And unfortunately, in early versions of Windows that supported Active Directory — Windows 2000 Server, for example — the default or example Active Directory path was given as “corp,” and many companies apparently adopted this setting without modifying it to include a domain they controlled.

Compounding things further, some companies then went on to build (and/or assimilate) vast networks of networks on top of this erroneous setting.

Now, none of this was much of a security concern back in the day when it was impractical for employees to lug their bulky desktop computers and monitors outside of the corporate network. But what happens when an employee working at a company with an Active Directory network path called “corp” takes a company laptop to the local Starbucks?

Chances are good that at least some resources on the employee’s laptop will still try to access that internal “corp” domain. And because of the way DNS name devolution works on Windows, that company laptop online via the Starbucks wireless connection is likely to then seek those same resources at “corp.com.”

In practical terms, this means that whoever controls corp.com can passively intercept private communications from hundreds of thousands of computers that end up being taken outside of a corporate environment which uses this “corp” designation for its Active Directory domain.

The story went on to describe how years of testing — some of which was subsidized by grants from the U.S. Department of Homeland Security — showed hundreds of thousands of Windows computers were constantly trying to send this domain information it had no business receiving, including attempts to log in to internal corporate networks and access specific file shares on those networks.

O’Connor told me he was selling the domain after doing basically nothing with it for 26 years because he was getting on in years and didn’t want his kids to inherit this mess. When he put the domain up for sale, I asked if he’d agree to let me know if and when he sold it.

On Monday evening, he wrote to say that Microsoft had agreed to purchase it. O’Connor said he could  not discuss the terms of the deal, nor could he offer further comment beyond acknowledging the sale of corp.com to Microsoft. Continue reading →


02
Apr 20

‘War Dialing’ Tool Exposes Zoom’s Password Problems

As the Coronavirus pandemic continues to force people to work from home, countless companies are now holding daily meetings using videoconferencing services from Zoom. But without the protection of a password, there’s a decent chance your next Zoom meeting could be “Zoom bombed” — attended or disrupted by someone who doesn’t belong. And according to data gathered by a new automated Zoom meeting discovery tool dubbed “zWarDial,” a crazy number of meetings at major corporations are not being protected by a password.

zWarDial, an automated tool for finding non-password protected Zoom meetings. According to its makers, zWarDial can find on average 110 meetings per hour, and has a success rate of around 14 percent.

Each Zoom conference call is assigned a Meeting ID that consists of 9 to 11 digits. Naturally, hackers have figured out they can simply guess or automate the guessing of random IDs within that space of digits.

Security experts at Check Point Research did exactly that last summer, and found they were able to predict approximately four percent of randomly generated Meeting IDs. The Check Point researchers said enabling passwords on each meeting was the only thing that prevented them from randomly finding a meeting.

Zoom responded by saying it was enabling passwords by default in all future scheduled meetings. Zoom also said it would block repeated attempts to scan for meeting IDs, and that it would no longer automatically indicate if a meeting ID was valid or invalid.

Nevertheless, the incidence of Zoombombing has skyrocketed over the past few weeks, even prompting an alert by the FBI on how to secure meetings against eavesdroppers and mischief-makers. This suggests that many Zoom users have disabled passwords by default and/or that Zoom’s new security feature simply isn’t working as intended for all users.

New data and acknowledgments by Zoom itself suggest the latter may be more likely.

Earlier this week, KrebsOnSecurity heard from Trent Lo, a security professional and co-founder of SecKC, Kansas City’s longest-running monthly security meetup. Lo and fellow SecKC members recently created zWarDial, which borrows part of its name from the old phone-based war dialing programs that called random or sequential numbers in a given telephone number prefix to search for computer modems.

Lo said zWarDial evades Zoom’s attempts to block automated meeting scans by routing the searches through multiple proxies in Tor, a free and open-source software that lets users browse the Web anonymously.

“Zoom recently said they fixed this but I’m using a totally different URL and passing a cookie along with that URL,” Lo said, describing part of how the tool works on the back end. “This gives me the [Zoom meeting] room information without having to log in.”

Lo said a single instance of zWarDial can find approximately 100 meetings per hour, but that multiple instances of the tool running in parallel could probably discover most of the open Zoom meetings on any given day. Each instance, he said, has a success rate of approximately 14 percent, meaning for each random meeting number it tries, the program has a 14 percent chance of finding an open meeting.

Only meetings that are protected by a password are undetectable by zWarDial, Lo said.

“Having a password enabled on the meeting is the only thing that defeats it,” he said.

Lo shared the output of one day’s worth of zWarDial scanning, which revealed information about nearly 2,400 upcoming or recurring Zoom meetings. That information included the link needed to join each meeting; the date and time of the meeting; the name of the meeting organizer; and any information supplied by the meeting organizer about the topic of the meeting.

The results were staggering, and revealed details about Zoom meetings scheduled by some of the world’s largest companies, including major banks, international consulting firms, ride-hailing services, government contractors, and investment ratings firms.

KrebsOnSecurity is not naming the companies involved, but was able to verify dozens of them by matching the name of the meeting organizer with corporate profiles on LinkedIn.

By far the largest group of companies exposing their Zoom meetings are in the technology sector, and include a number of security and cloud technology vendors. These include at least one tech company that’s taken to social media warning people about the need to password protect Zoom meetings!

The distribution of Zoom meetings found by zWarDial, indexed by industry. As depicted above, zWarDial found roughly 2,400 exposed meetings in less than 24 hours. Image: SecKC.

Continue reading →