Posts Tagged: microsoft


16
Dec 20

Malicious Domain in SolarWinds Hack Turned into ‘Killswitch’

A key malicious domain name used to control potentially thousands of computer systems compromised via the months-long breach at network monitoring software vendor SolarWinds was commandeered by security experts and used as a “killswitch” designed to turn the sprawling cybercrime operation against itself, KrebsOnSecurity has learned.

Austin, Texas-based SolarWinds disclosed this week that a compromise of its software update servers earlier this year may have resulted in malicious code being pushed to nearly 18,000 customers of its Orion platform. Many U.S. federal agencies and Fortune 500 firms use(d) Orion to monitor the health of their IT networks.

On Dec. 13, cyber incident response firm FireEye published a detailed writeup on the malware infrastructure used in the SolarWinds compromise, presenting evidence that the Orion software was first compromised back in March 2020. FireEye said hacked networks were seen communicating with a malicious domain name — avsvmcloud[.]com — one of several domains the attackers had set up to control affected systems.

As first reported here on Tuesday, there were signs over the past few days that control over the domain had been transferred to Microsoft. Asked about the changeover, Microsoft referred questions to FireEye and to GoDaddy, the current domain name registrar for the malicious site.

Today, FireEye responded that the domain seizure was part of a collaborative effort to prevent networks that may have been affected by the compromised SolarWinds software update from communicating with the attackers. What’s more, the company said the domain was reconfigured to act as a “killswitch” that would prevent the malware from continuing to operate in some circumstances.

“SUNBURST is the malware that was distributed through SolarWinds software,” FireEye said in a statement shared with KrebsOnSecurity. “As part of FireEye’s analysis of SUNBURST, we identified a killswitch that would prevent SUNBURST from continuing to operate.”

The statement continues:

“Depending on the IP address returned when the malware resolves avsvmcloud[.]com, under certain conditions, the malware would terminate itself and prevent further execution. FireEye collaborated with GoDaddy and Microsoft to deactivate SUNBURST infections.”

“This killswitch will affect new and previous SUNBURST infections by disabling SUNBURST deployments that are still beaconing to avsvmcloud[.]com. However, in the intrusions FireEye has seen, this actor moved quickly to establish additional persistent mechanisms to access to victim networks beyond the SUNBURST backdoor.

This killswitch will not remove the actor from victim networks where they have established other backdoors. However, it will make it more difficult to for the actor to leverage the previously distributed versions of SUNBURST.”

It is likely that given their visibility into and control over the malicious domain, Microsoft, FireEye, GoDaddy and others now have a decent idea which companies may still be struggling with SUNBURST infections.

The killswitch revelations came as security researchers said they’d made progress in decoding SUNBURST’s obfuscated communications methods. Chinese cybersecurity firm RedDrip Team published their findings on Github, saying its decoder tool had identified nearly a hundred suspected victims of the SolarWinds/Orion breach, including universities, governments and high tech companies.

Meanwhile, the potential legal fallout for SolarWinds in the wake of this breach continues to worsen. The Washington Post reported Tuesday that top investors in SolarWinds sold millions of dollars in stock in the days before the intrusion was revealed. SolarWinds’s stock price has fallen more than 20 percent in the past few days. The Post cited former enforcement officials at the U.S. Securities and Exchange Commission (SEC) saying the sales were likely to prompt an insider trading investigation.


15
Dec 20

SolarWinds Hack Could Affect 18K Customers

The still-unfolding breach at network management software firm SolarWinds may have resulted in malicious code being pushed to nearly 18,000 customers, the company said in a legal filing on Monday. Meanwhile, Microsoft should soon have some idea which and how many SolarWinds customers were affected, as it recently took possession of a key domain name used by the intruders to control infected systems.

On Dec. 13, SolarWinds acknowledged that hackers had inserted malware into a service that provided software updates for its Orion platform, a suite of products broadly used across the U.S. federal government and Fortune 500 firms to monitor the health of their IT networks.

In a Dec. 14 filing with the U.S. Securities and Exchange Commission (SEC), SolarWinds said roughly 33,000 of its more than 300,000 customers were Orion customers, and that fewer than 18,000 customers may have had an installation of the Orion product that contained the malicious code. SolarWinds said the intrusion also compromised its Microsoft Office 365 accounts.

The initial breach disclosure from SolarWinds came five days after cybersecurity incident response firm FireEye announced it had suffered an intrusion that resulted in the theft of some 300 proprietary software tools the company provides to clients to help secure their IT operations.

On Dec. 13, FireEye published a detailed writeup on the malware infrastructure used in the SolarWinds compromise, presenting evidence that the Orion software was first compromised back in March 2020. FireEye didn’t explicitly say its own intrusion was the result of the SolarWinds hack, but the company confirmed as much to KrebsOnSecurity earlier today.

Also on Dec. 13, news broke that the SolarWinds hack resulted in attackers reading the email communications at the U.S. Treasury and Commerce departments.

On Dec. 14, Reuters reported the SolarWinds intrusion also had been used to infiltrate computer networks at the U.S. Department of Homeland Security (DHS). That disclosure came less than 24 hours after DHS’s Cybersecurity and Infrastructure Security Agency (CISA) took the unusual step of issuing an emergency directive ordering all federal agencies to immediately disconnect the affected Orion products from their networks.

ANALYSIS

Security experts have been speculating as to the extent of the damage from the SolarWinds hack, combing through details in the FireEye analysis and elsewhere for clues about how many other organizations may have been hit.

And it seems that Microsoft may now be in perhaps the best position to take stock of the carnage. That’s because sometime on Dec. 14, the software giant took control over a key domain name — avsvmcloud[.]com — that was used by the SolarWinds hackers to communicate with systems compromised by the backdoored Orion product updates.

Armed with that access, Microsoft should be able to tell which organizations have IT systems that are still trying to ping the malicious domain. However, because many Internet service providers and affected companies are already blocking systems from accessing that malicious control domain or have disconnected the vulnerable Orion services, Microsoft’s visibility may be somewhat limited.

Microsoft has a long history of working with federal investigators and the U.S. courts to seize control over domains involved in global malware menaces, particularly when those sites are being used primarily to attack Microsoft Windows customers.

Microsoft dodged direct questions about its visibility into the malware control domain, suggesting those queries would be better put to FireEye or GoDaddy (the current domain registrar for the malware control server). But in a response on Twitter, Microsoft spokesperson Jeff Jones seemed to confirm that control of the malicious domain had changed hands. Continue reading →


14
Dec 20

U.S. Treasury, Commerce Depts. Hacked Through SolarWinds Compromise

Communications at the U.S. Treasury and Commerce Departments were reportedly compromised by a supply chain attack on SolarWinds, a security vendor that helps the federal government and a range of Fortune 500 companies monitor the health of their IT networks. Given the breadth of the company’s customer base, experts say the incident may be just the first of many such disclosures.

Some of SolarWinds’ customers. Source: solarwinds.com

According to a Reuters story, hackers believed to be working for Russia have been monitoring internal email traffic at the U.S. Treasury and Commerce departments. Reuters reports the attackers were able to surreptitiously tamper with updates released by SolarWinds for its Orion platform, a suite of network management tools.

In a security advisory, Austin, Texas based SolarWinds acknowledged its systems “experienced a highly sophisticated, manual supply chain attack on SolarWinds Orion Platform software builds for versions 2019.4 HF 5 through 2020.2.1, released between March 2020 and June 2020.”

In response to the intrusions at Treasury and Commerce, the Department of Homeland Security’s Cybersecurity and Infrastructure Security Agency (CISA) took the unusual step of issuing an emergency directive ordering all federal agencies to immediately disconnect the affected Orion products from their networks.

“Treat all hosts monitored by the SolarWinds Orion monitoring software as compromised by threat actors and assume that further persistence mechanisms have been deployed,” CISA advised.

A blog post by Microsoft says the attackers were able to add malicious code to software updates provided by SolarWinds for Orion users. “This results in the attacker gaining a foothold in the network, which the attacker can use to gain elevated credentials,” Microsoft wrote.

From there, the attackers would be able to forge single sign-on tokens that impersonate any of the organization’s existing users and accounts, including highly privileged accounts on the network.

“Using highly privileged accounts acquired through the technique above or other means, attackers may add their own credentials to existing application service principals, enabling them to call APIs with the permission assigned to that application,” Microsoft explained.

Malicious code added to an Orion software update may have gone undetected by antivirus software and other security tools on host systems thanks in part to guidance from SolarWinds itself. In this support advisory, SolarWinds says its products may not work properly unless their file directories are exempted from antivirus scans and group policy object restrictions. Continue reading →


29
Sep 20

Who’s Behind Monday’s 14-State 911 Outage?

Emergency 911 systems were down for more than an hour on Monday in towns and cities across 14 U.S. states. The outages led many news outlets to speculate the problem was related to Microsoft‘s Azure web services platform, which also was struggling with a widespread outage at the time. However, multiple sources tell KrebsOnSecurity the 911 issues stemmed from some kind of technical snafu involving Intrado and Lumen, two companies that together handle 911 calls for a broad swath of the United States.

Image: West.com

On the afternoon of Monday, Sept. 28, several states including Arizona, California, Colorado, Delaware, Florida, Illinois, Indiana, Minnesota, Nevada, North Carolina, North Dakota, Ohio, Pennsylvania and Washington reported 911 outages in various cities and localities.

Multiple news reports suggested the outages might have been related to an ongoing service disruption at Microsoft. But a spokesperson for the software giant told KrebsOnSecurity, “we’ve seen no indication that the multi-state 911 outage was a result of yesterday’s Azure service disruption.”

Inquiries made with emergency dispatch centers at several of the towns and cities hit by the 911 outage pointed to a different source: Omaha, Neb.-based Intrado — until last year known as West Safety Communications — a provider of 911 and emergency communications infrastructure, systems and services to telecommunications companies and public safety agencies throughout the country.

Intrado did not respond to multiple requests for comment. But according to officials in Henderson County, NC, which experienced its own 911 failures yesterday, Intrado said the outage was the result of a problem with an unspecified service provider.

“On September 28, 2020, at 4:30pm MT, our 911 Service Provider observed conditions internal to their network that resulted in impacts to 911 call delivery,” reads a statement Intrado provided to county officials. “The impact was mitigated, and service was restored and confirmed to be functional by 5:47PM MT.  Our service provider is currently working to determine root cause.”

The service provider referenced in Intrado’s statement appears to be Lumen, a communications firm and 911 provider that until very recently was known as CenturyLink Inc. A look at the company’s status page indicates multiple Lumen systems experienced total or partial service disruptions on Monday, including its private and internal cloud networks and its control systems network.

Lumen’s status page indicates the company’s private and internal cloud and control system networks had outages or service disruptions on Monday.

In a statement provided to KrebsOnSecurity, Lumen blamed the issue on Intrado.

“At approximately 4:30 p.m. MT, some Lumen customers were affected by a vendor partner event that impacted 911 services in AZ, CO, NC, ND, MN, SD, and UT,” the statement reads. “Service was restored in less than an hour and all 911 traffic is routing properly at this time. The vendor partner is in the process of investigating the event.”

It may be no accident that both of these companies are now operating under new names, as this would hardly be the first time a problem between the two of them has disrupted 911 access for a large number of Americans. Continue reading →


24
Sep 20

Microsoft: Attackers Exploiting ‘ZeroLogon’ Windows Flaw

Microsoft warned on Wednesday that malicious hackers are exploiting a particularly dangerous flaw in Windows Server systems that could be used to give attackers the keys to the kingdom inside a vulnerable corporate network. Microsoft’s warning comes just days after the U.S. Department of Homeland Security issued an emergency directive instructing all federal agencies to patch the vulnerability by Sept. 21 at the latest.

DHS’s Cybersecurity and Infrastructure Agency (CISA) said in the directive that it expected imminent exploitation of the flaw — CVE-2020-1472 and dubbed “ZeroLogon” — because exploit code which can be used to take advantage of it was circulating online.

Last night, Microsoft’s Security Intelligence unit tweeted that the company is “tracking threat actor activity using exploits for the CVE-2020-1472 Netlogon vulnerability.”

“We have observed attacks where public exploits have been incorporated into attacker playbooks,” Microsoft said. “We strongly recommend customers to immediately apply security updates.”

Microsoft released a patch for the vulnerability in August, but it is not uncommon for businesses to delay deploying updates for days or weeks while testing to ensure the fixes do not interfere with or disrupt specific applications and software.

CVE-2020-1472 earned Microsoft’s most-dire “critical” severity rating, meaning attackers can exploit it with little or no help from users. The flaw is present in most supported versions of Windows Server, from Server 2008 through Server 2019. Continue reading →


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 →


7
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 →


29
Jan 20

Sprint Exposed Customer Support Site to Web

Fresh on the heels of a disclosure that Microsoft Corp. leaked internal customer support data to the Internet, mobile provider Sprint has addressed a mix-up in which posts to a private customer support community were exposed to the Web.

KrebsOnSecurity recently contacted Sprint to let the company know that an internal customer support forum called “Social Care” was being indexed by search engines, and that several months worth of postings about customer complaints and other issues were viewable without authentication to anyone with a Web browser.

A redacted screen shot of one Sprint customer support thread exposed to the Web.

A Sprint spokesperson responded that the forum was indeed intended to be a private section of its support community, but that an error caused the section to become public.

“These conversations include minimal customer information and are used for frontline reps to escalate issues to managers,” said Lisa Belot, Sprint’s communications manager.

A review of the exposed support forum by this author suggests that while none of the posts exposed customer information such as payment card data, a number of them did include customer account information, such customer names, device identifiers and in some cases location information.

Perhaps more importantly for Sprint and its customers, the forum also included numerous links and references to internal tools and procedures. This sort of information would no doubt be of interest to scammers seeking to conduct social engineering attacks against Sprint employees as way to perpetrate other types of fraud, including unauthorized SIM swaps or in gleaning more account information from targeted customers. Continue reading →


13
Jan 20

Cryptic Rumblings Ahead of First 2020 Patch Tuesday

Sources tell KrebsOnSecurity that Microsoft Corp. is slated to release a software update on Tuesday to fix an extraordinarily serious security vulnerability in a core cryptographic component present in all versions of Windows. Those sources say Microsoft has quietly shipped a patch for the bug to branches of the U.S. military and to other high-value customers/targets that manage key Internet infrastructure, and that those organizations have been asked to sign agreements preventing them from disclosing details of the flaw prior to Jan. 14, the first Patch Tuesday of 2020.

According to sources, the vulnerability in question resides in a Windows component known as crypt32.dll, a Windows module that Microsoft says handles “certificate and cryptographic messaging functions in the CryptoAPI.” The Microsoft CryptoAPI provides services that enable developers to secure Windows-based applications using cryptography, and includes functionality for encrypting and decrypting data using digital certificates.

A critical vulnerability in this Windows component could have wide-ranging security implications for a number of important Windows functions, including authentication on Windows desktops and servers, the protection of sensitive data handled by Microsoft’s Internet Explorer/Edge browsers, as well as a number of third-party applications and tools.

Equally concerning, a flaw in crypt32.dll might also be abused to spoof the digital signature tied to a specific piece of software. Such a weakness could be exploited by attackers to make malware appear to be a benign program that was produced and signed by a legitimate software company.

This component was introduced into Windows more than 20 years ago — back in Windows NT 4.0. Consequently, all versions of Windows are likely affected (including Windows XP, which is no longer being supported with patches from Microsoft).

Microsoft has not yet responded to requests for comment. However, KrebsOnSecurity has heard rumblings from several sources over the past 48 hours that this Patch Tuesday (tomorrow) will include a doozy of an update that will need to be addressed immediately by all organizations running Windows.

Update 7:49 p.m. ET: Microsoft responded, saying that it does not discuss the details of reported vulnerabilities before an update is available. The company also said it does “not release production-ready updates ahead of regular Update Tuesday schedule. “Through our Security Update Validation Program (SUVP), we release advance versions of our updates for the purpose of validation and interoperability testing in lab environments,” Microsoft said in a written statement. “Participants in this program are contractually disallowed from applying the fix to any system outside of this purpose and may not apply it to production infrastructure.”

Continue reading →


12
Nov 19

Patch Tuesday, November 2019 Edition

Microsoft today released updates to plug security holes in its software, including patches to fix at least 74 weaknesses in various flavors of Windows and programs that run on top of it. The November updates include patches for a zero-day flaw in Internet Explorer that is currently being exploited in the wild, as well as a sneaky bug in certain versions of Office for Mac that bypasses security protections and was detailed publicly prior to today’s patches.

More than a dozen of the flaws tackled in this month’s release are rated “critical,” meaning they involve weaknesses that could be exploited to install malware without any action on the part of the user, except for perhaps browsing to a hacked or malicious Web site or opening a booby-trapped file attachment.

Perhaps the most concerning of those critical holes is a zero-day flaw in Internet Exploder Explorer (CVE-2019-1429) that has already seen active exploitation. Today’s updates also address two other critical vulnerabilities in the same Windows component that handles various scripting languages.

Microsoft also fixed a flaw in Microsoft Office for Mac (CVE-2019-1457) that could allow attackers to bypass security protections in some versions of the program.

Macros are bits of computer code that can be embedded into Office files, and malicious macros are frequently used by malware purveyors to compromise Windows systems. Usually, this takes the form of a prompt urging the user to “enable macros” once they’ve opened a booby-trapped Office document delivered via email. Thus, Office has a feature called “disable all macros without notification.”

But Microsoft says all versions of Office still support an older type of macros that do not respect this setting, and can be used as a vector for pushing malwareWill Dormann of the CERT/CC has reported that Office 2016 and 2019 for Mac will fail to prompt the user before executing these older macro types if the “Disable all macros without notification” setting is used. Continue reading →