Category: Security Tools

Security Tools

Microsoft Patch Tuesday, February 2021 Edition

Microsoft today rolled out updates to plug at least 56 security holes in its Windows operating systems and other software. One of the bugs is already being actively exploited, and six of them were publicized prior to today, potentially giving attackers a head start in figuring out how to exploit the flaws.

Nine of the 56 vulnerabilities earned Microsoft’s most urgent “critical” rating, meaning malware or miscreants could use them to seize remote control over unpatched systems with little or no help from users.

The flaw being exploited in the wild already — CVE-2021-1732 — affects Windows 10, Server 2016 and later editions. It received a slightly less dire “important” rating and mainly because it is a vulnerability that lets an attacker increase their authority and control on a device, which means the attacker needs to already have access to the target system.

Two of the other bugs that were disclosed prior to this week are critical and reside in Microsoft’s .NET Framework, a component required by many third-party applications (most Windows users will have some version of .NET installed). Continue reading →

Patch Tuesday, Good Riddance 2020 Edition

Microsoft today issued its final batch of security updates for Windows PCs in 2020, ending the year with a relatively light patch load. Nine of the 58 security vulnerabilities addressed this month earned Microsoft’s most-dire “critical” label, meaning they can be abused by malware or miscreants to seize remote control over PCs without any help from users.

Mercifully, it does not appear that any of the flaws fixed this month are being actively exploited, nor have any them been detailed publicly prior to today.

The critical bits reside in updates for Microsoft Exchange Server, Sharepoint Server, and Windows 10 and Server 2016 systems. Additionally, Microsoft released an advisory on how to minimize the risk from a DNS spoofing weakness in Windows Server 2008 through 2019.

Some of the sub-critical “important” flaws addressed this month also probably deserve prompt patching in enterprise environments, including a trio of updates tackling security issues with Microsoft Office.

“Given the speed with which attackers often weaponize Microsoft Office vulnerabilities, these should be prioritized in patching,” said Allan Liska, senior security architect at Recorded Future. “The vulnerabilities, if exploited, would allow an attacker to execute arbitrary code on a victim’s machine. These vulnerabilities affect Microsoft Excel 2013 through 2019, Microsoft 365 32 and 64 bit versions, Microsoft Office 2019 32 and 64 bit versions, and Microsoft Excel for Mac 2019.”

We also learned this week that Redmond quietly addressed a scary “zero-click” vulnerability in its Microsoft Teams platform that would have let anyone execute code of their choosing just by sending the target a specially-crafted chat message to a Teams users. The bug was cross-platform, meaning it could also have been used to deliver malicious code to people using Teams on non-Windows devices. Continue reading →

Security Tools / Tax Refund Fraud — 84 Comments
4
Dec 20

IRS to Make ID Protection PIN Open to All

The U.S. Internal Revenue Service (IRS) said this week that beginning in 2021 it will allow all taxpayers to apply for an identity protection personal identification number (IP PIN), a single-use code designed to block identity thieves from falsely claiming a tax refund in your name. Currently, IP PINs are issued only to those who fill out an ID theft affidavit, or to taxpayers who’ve experienced tax refund fraud in previous years.

Tax refund fraud is a perennial problem involving the use of identity information and often stolen or misdirected W-2 forms to electronically file an unauthorized tax return for the purposes of claiming a refund in the name of a taxpayer.

Victims usually first learn of the crime after having their returns rejected because scammers beat them to it. Even those who are not required to file a return can be victims of refund fraud, as can those who are not actually due a refund from the IRS.

Many of the reasons why refund fraud remains a problem have to do with timing, and some of them are described in more detail here. But the short answer is the IRS is under tremendous pressure to issue refunds quickly and to minimize “false positives” (flagging legitimate claims as fraud) — even when it may not yet have all of the information needed to accurately distinguish phony filings from legitimate ones. Continue reading →

Security Tools / Time to Patch — 35 Comments
10
Nov 20

Patch Tuesday, November 2020 Edition

Adobe and Microsoft each issued a bevy of updates today to plug critical security holes in their software. Microsoft’s release includes fixes for 112 separate flaws, including one zero-day vulnerability that is already being exploited to attack Windows users. Microsoft also is taking flak for changing its security advisories and limiting the amount of information disclosed about each bug.

Some 17 of the 112 issues fixed in today’s patch batch involve “critical” problems in Windows, or those that can be exploited by malware or malcontents to seize complete, remote control over a vulnerable Windows computer without any help from users.

Most of the rest were assigned the rating “important,” which in Redmond parlance refers to a vulnerability whose exploitation could “compromise the confidentiality, integrity, or availability of user data, or of the integrity or availability of processing resources.”

A chief concern among all these updates this month is CVE-2020-17087, which is an “important” bug in the Windows kernel that is already seeing active exploitation. CVE-2020-17087 is not listed as critical because it’s what’s known as a privilege escalation flaw that would allow an attacker who has already compromised a less powerful user account on a system to gain administrative control. In essence, it would have to be chained with another exploit.

Unfortunately, this is exactly what Google researchers described witnessing recently. On Oct. 20, Google released an update for its Chrome browser which fixed a bug (CVE-2020-15999) that was seen being used in conjunction with CVE-2020-17087 to compromise Windows users.

If you take a look at the advisory Microsoft released today for CVE-2020-17087 (or any others from today’s batch), you might notice they look a bit more sparse. That’s because Microsoft has opted to restructure those advisories around the Common Vulnerability Scoring System (CVSS) format to more closely align the format of the advisories with that of other major software vendors.

But in so doing, Microsoft has also removed some useful information, such as the description explaining in broad terms the scope of the vulnerability, how it can be exploited, and what the result of the exploitation might be. Microsoft explained its reasoning behind this shift in a blog post.

Not everyone is happy with the new format. Bob Huber, chief security officer at Tenable, praised Microsoft for adopting an industry standard, but said the company should consider that folks who review Patch Tuesday releases aren’t security practitioners but rather IT counterparts responsible for actually applying the updates who often aren’t able (and shouldn’t have to) decipher raw CVSS data.

“With this new format, end users are completely blind to how a particular CVE impacts them,” Huber said. “What’s more, this makes it nearly impossible to determine the urgency of a given patch. It’s difficult to understand the benefits to end-users. However, it’s not too difficult to see how this new format benefits bad actors. They’ll reverse engineer the patches and, by Microsoft not being explicit about vulnerability details, the advantage goes to attackers, not defenders. Without the proper context for these CVEs, it becomes increasingly difficult for defenders to prioritize their remediation efforts.” Continue reading →

Security Tools / Time to Patch — 56 Comments
8
Sep 20

Microsoft Patch Tuesday, Sept. 2020 Edition

Microsoft today released updates to remedy nearly 130 security vulnerabilities in its Windows operating system and supported software. None of the flaws are known to be currently under active exploitation, but 23 of them could be exploited by malware or malcontents to seize complete control of Windows computers with little or no help from users.

The majority of the most dangerous or “critical” bugs deal with issues in Microsoft’s various Windows operating systems and its web browsers, Internet Explorer and Edge. September marks the seventh month in a row Microsoft has shipped fixes for more than 100 flaws in its products, and the fourth month in a row that it fixed more than 120.

Among the chief concerns for enterprises this month is CVE-2020-16875, which involves a critical flaw in the email software Microsoft Exchange Server 2016 and 2019. An attacker could leverage the Exchange bug to run code of his choosing just by sending a booby-trapped email to a vulnerable Exchange server.

“That doesn’t quite make it wormable, but it’s about the worst-case scenario for Exchange servers,” said Dustin Childs, of Trend Micro’s Zero Day Initiative. “We have seen the previously patched Exchange bug CVE-2020-0688 used in the wild, and that requires authentication. We’ll likely see this one in the wild soon. This should be your top priority.”

Also not great for companies to have around is CVE-2020-1210, which is a remote code execution flaw in supported versions of Microsoft Sharepoint document management software that bad guys could attack by uploading a file to a vulnerable Sharepoint site. Security firm Tenable notes that this bug is reminiscent of CVE-2019-0604, another Sharepoint problem that’s been exploited for cybercriminal gains since April 2019.

Microsoft fixed at least five other serious bugs in Sharepoint versions 2010 through 2019 that also could be used to compromise systems running this software. And because ransomware purveyors have a history of seizing upon Sharepoint flaws to wreak havoc inside enterprises, companies should definitely prioritize deployment of these fixes, says Alan Liska, senior security architect at Recorded Future. Continue reading →

Latest Warnings / Security Tools / The Coming Storm — 20 Comments
21
Aug 20

FBI, CISA Echo Warnings on ‘Vishing’ Threat

The Federal Bureau of Investigation (FBI) and the Cybersecurity and Infrastructure Security Agency (CISA) on Thursday issued a joint alert to warn about the growing threat from voice phishing or “vishing” attacks targeting companies. The advisory came less than 24 hours after KrebsOnSecurity published an in-depth look at a crime group offering a service that people can hire to steal VPN credentials and other sensitive data from employees working remotely during the Coronavirus pandemic.

“The COVID-19 pandemic has resulted in a mass shift to working from home, resulting in increased use of corporate virtual private networks (VPNs) and elimination of in-person verification,” the alert reads. “In mid-July 2020, cybercriminals started a vishing campaign—gaining access to employee tools at multiple companies with indiscriminate targeting — with the end goal of monetizing the access.”

As noted in Wednesday’s story, the agencies said the phishing sites set up by the attackers tend to include hyphens, the target company’s name, and certain words — such as “support,” “ticket,” and “employee.” The perpetrators focus on social engineering new hires at the targeted company, and impersonate staff at the target company’s IT helpdesk.

The joint FBI/CISA alert (PDF) says the vishing gang also compiles dossiers on employees at the specific companies using mass scraping of public profiles on social media platforms, recruiter and marketing tools, publicly available background check services, and open-source research. From the alert:

“Actors first began using unattributed Voice over Internet Protocol (VoIP) numbers to call targeted employees on their personal cellphones, and later began incorporating spoofed numbers of other offices and employees in the victim company. The actors used social engineering techniques and, in some cases, posed as members of the victim company’s IT help desk, using their knowledge of the employee’s personally identifiable information—including name, position, duration at company, and home address—to gain the trust of the targeted employee.”

“The actors then convinced the targeted employee that a new VPN link would be sent and required their login, including any 2FA [2-factor authentication] or OTP [one-time passwords]. The actor logged the information provided by the employee and used it in real-time to gain access to corporate tools using the employee’s account.”

The alert notes that in some cases the unsuspecting employees approved the 2FA or OTP prompt, either accidentally or believing it was the result of the earlier access granted to the help desk impersonator. In other cases, the attackers were able to intercept the one-time codes by targeting the employee with SIM swapping, which involves social engineering people at mobile phone companies into giving them control of the target’s phone number. Continue reading →

Security Tools — 122 Comments
12
Aug 20

Why & Where You Should Plant Your Flag

Several stories here have highlighted the importance of creating accounts online tied to your various identity, financial and communications services before identity thieves do it for you. This post examines some of the key places where everyone should plant their virtual flags.

As KrebsOnSecurity observed back in 2018, many people — particularly older folks — proudly declare they avoid using the Web to manage various accounts tied to their personal and financial data — including everything from utilities and mobile phones to retirement benefits and online banking services. From that story:

“The reasoning behind this strategy is as simple as it is alluring: What’s not put online can’t be hacked. But increasingly, adherents to this mantra are finding out the hard way that if you don’t plant your flag online, fraudsters and identity thieves may do it for you.”

“The crux of the problem is that while most types of customer accounts these days can be managed online, the process of tying one’s account number to a specific email address and/or mobile device typically involves supplying personal data that can easily be found or purchased online — such as Social Security numbers, birthdays and addresses.”

In short, although you may not be required to create online accounts to manage your affairs at your ISP, the U.S. Postal Service, the credit bureaus or the Social Security Administration, it’s a good idea to do so for several reasons.

Most importantly, the majority of the entities I’ll discuss here allow just one registrant per person/customer. Thus, even if you have no intention of using that account, establishing one will be far easier than trying to dislodge an impostor who gets there first using your identity data and an email address they control.

Also, the cost of planting your flag is virtually nil apart from your investment of time. In contrast, failing to plant one’s flag can allow ne’er-do-wells to create a great deal of mischief for you, whether it be misdirecting your service or benefits elsewhere, or canceling them altogether.

Before we dive into the list, a couple of important caveats. Adding multi-factor authentication (MFA) at these various providers (where available) and/or establishing a customer-specific personal identification number (PIN) also can help secure online access. For those who can’t be convinced to use a password manager, even writing down all of the account details and passwords on a slip of paper can be helpful, provided the document is secured in a safe place.

Perhaps the most important place to enable MFA is with your email accounts. Armed with access to your inbox, thieves can then reset the password for any other service or account that is tied to that email address.

People who don’t take advantage of these added safeguards may find it far more difficult to regain access when their account gets hacked, because increasingly thieves will enable multi-factor options and tie the account to a device they control.

Secondly, guard the security of your mobile phone account as best you can (doing so might just save your life). The passwords for countless online services can be reset merely by entering a one-time code sent via text message to the phone number on file for the customer’s account.

And thanks to the increasing prevalence of a crime known as SIM swapping, thieves may be able to upend your personal and financial life simply by tricking someone at your mobile service provider into diverting your calls and texts to a device they control.

Most mobile providers offer customers the option of placing a PIN or secret passphrase on their accounts to lessen the likelihood of such attacks succeeding, but these protections also usually fail when the attackers are social engineering some $12-an-hour employee at a mobile phone store.

Your best option is to reduce your overall reliance on your phone number for added authentication at any online service. Many sites now offer MFA options that are app-based and not tied to your mobile service, and this is your best option for MFA wherever possible. Continue reading →

A Little Sunshine / Security Tools — 79 Comments
4
Jul 20

E-Verify’s “SSN Lock” is Nothing of the Sort

One of the most-read advice columns on this site is a 2018 piece called “Plant Your Flag, Mark Your Territory,” which tried to impress upon readers the importance of creating accounts at websites like those at the Social Security Administration, the IRS and others before crooks do it for you. A key concept here is that these services only allow one account per Social Security number — which for better or worse is the de facto national identifier in the United States. But KrebsOnSecurity recently discovered that this is not the case with all federal government sites built to help you manage your identity online.

A reader who was recently the victim of unemployment insurance fraud said he was told he should create an account at the Department of Homeland Security‘s myE-Verify website, and place a lock on his Social Security number (SSN) to minimize the chances that ID thieves might abuse his identity for employment fraud in the future.

DHS’s myE-Verify homepage.

According to the website, roughly 600,000 employers at over 1.9 million hiring sites use E-Verify to confirm the employment eligibility of new employees. E-Verify’s consumer-facing portal myE-Verify lets users track and manage employment inquiries made through the E-Verify system. It also features a “Self Lock” designed to prevent the misuse of one’s SSN in E-Verify.

Enabling this lock is supposed to mean that for the next year thereafter, if an unauthorized individual attempts to fraudulently use a SSN for employment authorization, he or she cannot use the SSN in E-Verify, even if the SSN is that of an employment authorized individual. But in practice, this service may actually do little to deter ID thieves from impersonating you to a potential employer.

At the request of the reader who reached out (and in the interest of following my own advice to plant one’s flag), KrebsOnSecurity decided to sign up for a myE-Verify account. After verifying my email address, I was asked to pick a strong password and select a form of multi-factor authentication (MFA). The most secure MFA option offered (a one-time code generated by an app like Google Authenticator or Authy) was already pre-selected, so I chose that.

The site requested my name, address, SSN, date of birth and phone number. I was then asked to select five questions and answers that might be asked if I were to try to reset my password, such as “In what city/town did you meet your spouse,” and “What is the name of the company of your first paid job.” I chose long, gibberish answers that had nothing to do with the questions (yes, these password questions are next to useless for security and frequently are the cause of account takeovers, but we’ll get to that in a minute).

Password reset questions selected, the site proceeded to ask four, multiple-guess “knowledge-based authentication” questions to verify my identity. The U.S. Federal Trade Commission‘s primer page on preventing job-related ID theft says people who have placed a security freeze on their credit files with the major credit bureaus will need to lift or thaw the freeze before being able to answer these questions successfully at myE-Verify. However, I did not find that to be the case, even though my credit file has been frozen with the major bureaus for years.

After successfully answering the KBA questions (the answer to each was “none of the above,” by the way), the site declared I’d successfully created my account! I could then see that I had the option to place a “Self Lock” on my SSN within the E-Verify system.

Doing so required me to pick three more challenge questions and answers. The site didn’t explain why it was asking me to do this, but I assumed it would prompt me for the answers in the event that I later chose to unlock my SSN within E-Verify.

After selecting and answering those questions and clicking the “Lock my SSN” button, the site generated an error message saying something went wrong and it couldn’t proceed.

Alas, logging out and logging back in again showed that the site did in fact proceed and that my SSN was locked. Joy.

But I still had to know one thing: Could someone else come along pretending to be me and create another account using my SSN, date of birth and address but under a different email address? Using a different browser and Internet address, I proceeded to find out.

Imagine my surprise when I was able to create a separate account as me with just a different email address (once again, the correct answers to all of the KBA questions was “none of the above”). Upon logging in, I noticed my SSN was indeed locked within E-Verify. So I chose to unlock it.

Did the system ask any of the challenge questions it had me create previously? Nope. It just reported that my SSN was now unlocked. Logging out and logging back in to the original account I created (again under a different IP and browser) confirmed that my SSN was unlocked. Continue reading →

Latest Warnings / Security Tools — 83 Comments
19
Jun 20

Turn on MFA Before Crooks Do It For You

Hundreds of popular websites now offer some form of multi-factor authentication (MFA), which can help users safeguard access to accounts when their password is breached or stolen. But people who don’t take advantage of these added safeguards may find it far more difficult to regain access when their account gets hacked, because increasingly thieves will enable multi-factor options and tie the account to a device they control. Here’s the story of one such incident.

As a career chief privacy officer for different organizations, Dennis Dayman has tried to instill in his twin boys the importance of securing their online identities against account takeovers. Both are avid gamers on Microsoft’s Xbox platform, and for years their father managed their accounts via his own Microsoft account. But when the boys turned 18, they converted their child accounts to adult, effectively taking themselves out from under their dad’s control.

On a recent morning, one of Dayman’s sons found he could no longer access his Xbox account. The younger Dayman admitted to his dad that he’d reused his Xbox profile password elsewhere, and that he hadn’t enabled multi-factor authentication for the account.

When the two of them sat down to reset his password, the screen displayed a notice saying there was a new Gmail address tied to his Xbox account. When they went to turn on multi-factor authentication for his son’s Xbox profile — which was tied to a non-Microsoft email address — the Xbox service said it would send a notification of the change to unauthorized Gmail account in his profile.

Wary of alerting the hackers that they were wise to their intrusion, Dennis tried contacting Microsoft Xbox support, but found he couldn’t open a support ticket from a non-Microsoft account. Using his other son’s Outlook account, he filed a ticket about the incident with Microsoft.

Dennis soon learned the unauthorized Gmail address added to his son’s hacked Xbox account also had enabled MFA. Meaning, his son would be unable to reset the account’s password without approval from the person in control of the Gmail account.

Luckily for Dayman’s son, he hadn’t re-used the same password for the email address tied to his Xbox profile. Nevertheless, the thieves began abusing their access to purchase games on Xbox and third-party sites.

“During this period, we started realizing that his bank account was being drawn down through purchases of games from Xbox and [Electronic Arts],” Dayman the elder recalled. “I pulled the recovery codes for his Xbox account out of the safe, but because the hacker came in and turned on multi-factor, those codes were useless to us.”

Microsoft support sent Dayman and his son a list of 20 questions to answer about their account, such as the serial number on the Xbox console originally tied to the account when it was created. But despite answering all of those questions successfully, Microsoft refused to let them reset the password, Dayman said.

“They said their policy was not to turn over accounts to someone who couldn’t provide the second factor,” he said.

Dayman’s case was eventually escalated to Tier 3 Support at Microsoft, which was able to walk him through creating a new Microsoft account, enabling MFA on it, and then migrating his son’s Xbox profile over to the new account.

Microsoft told KrebsOnSecurity that while users currently are not prompted to enable two-step verification upon sign-up, they always have the option to enable the feature.

“Users are also prompted shortly after account creation to add additional security information if they have not yet done so, which enables the customer to receive security alerts and security promotions when they login to their account,” the company said in a written statement. “When we notice an unusual sign-in attempt from a new location or device, we help protect the account by challenging the login and send the user a notification. If a customer’s account is ever compromised, we will take the necessary steps to help them recover the account.” Continue reading →

Latest Warnings / Security Tools / Time to Patch — 42 Comments
9
Oct 19

Patch Tuesday Lowdown, October 2019 Edition

On Tuesday Microsoft issued software updates to fix almost five dozen security problems in Windows and software designed to run on top of it. By most accounts, it’s a relatively light patch batch this month. Here’s a look at the highlights.

Happily, only about 15 percent of the bugs patched this week earned Microsoft’s most dire “critical” rating. Microsoft labels flaws critical when they could be exploited by miscreants or malware to seize control over a vulnerable system without any help from the user.

Also, Adobe has kindly granted us another month’s respite from patching security holes in its Flash Player browser plugin.

Included in this month’s roundup is something Microsoft actually first started shipping in the third week of September, when it released an emergency update to fix a critical Internet Explorer zero-day flaw (CVE-2019-1367) that was being exploited in the wild. Continue reading →