CVE-2022-22279

Forecasting the Cyber Threat Landscape: What to Expect in 2023

Posted on by darklabhk

In a blink of an eye, 2023 is upon us. As we bid farewell to another record-breaking year of increased disclosed vulnerabilities, ransomware incidents, phishing scams, data breaches, and crypto heists, it is hard not to imagine that this year will be any less eventful as threat actors aggressively lower the barriers to entry of “cybercriminalism” by crowdsourcing their tasks. Based on PwC Dark Lab’s observations throughout 2022, we share our assessment of the potentially most prevalent threats and potential trends in the upcoming year.

Hackers will weaponise exploits at an even faster rate and scale to bypass heightened controls, thus achieving near-instant impact beyond initial access

Threat actors have demonstrated their increasing sophistication in speed and scale through the decreased timeframe required to weaponise critical vulnerabilities. In 2022, threat actors were able to weaponise critical vulnerabilities such as Zimbra Collaboration arbitrary memcache command injection (CVE-2022-27924) and FortiOS authentication bypass (CVE-2022-40684) within three (3) days of the Proof-of-Concepts (POCs) being published to perform unauthenticated remote code execution. In extreme cases such as Log4Shell (CVE-2021-44228), we observed that the weaponisation occurred a mere eight (8) hours after public release from our first incident response of the year (read more here).

Part of the reason why threat actors need to go faster is due to improved security controls of service providers. For example, Microsoft announced in February 2022 that Microsoft Office would automatically block Visual Basic Applications (VBA) macros in all downloaded documents by default in a phased rollout approach between April and June. As a result, we observed threat actors expeditiously developing novel exploits to perform client-site execution that bypasses the newly introduced security controls. [1] This includes the Mark-of-the-Web (MOTW) vulnerability (CVE-2022-44698) which allows for specially crafted ZIP and ISO files to be downloaded and executed without undergoing integrity checks on the user’s endpoint. [2] PwC’s Dark Lab has actively responded to an incident in August 2022 that observed the threat actor deploying Magniber ransomware after exploiting the MOTW vulnerability.

Meanwhile, exploit toolkits are not new but are being matured to an extent where threat actors of all sophistication can utilise to achieve near-instant impact beyond just initial access. In the cases of Zimbra (CVE-2022-27924) and FortiOS (CVE-2022-40684), our incident response experience suggests that threat actors likely leveraged exploit toolkits to automatically chain the POC exploit with standardised steps to establish persistence, perform discovery, move laterally, and achieve elevated privileges if applicable. As a result, victims that did not swiftly apply patches or workarounds to mitigate the risks associated with critical vulnerabilities likely needed to conduct intelligence-led threat hunting to ensure that their environment was not further impacted in any way.

We hypothesise that the rate and scale of weaponisation would further increase as threat actors look to find novel means to bypass increasingly mature security controls at an organisation’s external perimeter, aided by threat actors maturing their automated toolkits to maximise impact upon initial access. The number of vulnerabilities in 2022 had already grown at an inexorable rate of 25 percent from the previous year from 20,171 to 25,226[3], including the SonicWall SSL VPN post-authentication arbitrary file read vulnerability zero-day (CVE-2022-22279) [4] that Dark Lab discovered in an incident response case by the LockBit Ransomware-as-a-Service (RaaS) group in March 2022 (read more here). In that case, we uncovered during our incident response that the exploit code was actively being circulated and discussed on dark web forums in February 2022 and actively weaponised by several threat actors several days after disclosure to circumvent multi-factor authentication (MFA) access controls if they had access to valid credentials.

Human-operated ransomware threat actors will increase their sophistication to make-up the shortfalls of the Crypto winter

Human-operated ransomware attacks have dominated the cyber threat landscape over the past three years, booming just prior to the wake of the Covid-19 pandemic in 2020. This is largely attributed to the rise of RaaS, such as LockBit 3.0 and BlackCat who have lowered the barriers to entry for low-level threat actors by providing a subscription-based affiliate model offering custom-developed ransomware packages.

Even as the cryptocurrency markets falter, our monitoring of the overall number of listed victims on ransomware group leak sites has not dropped significantly throughout 2022. To put this into context, since the downfall of the prominent industry-leading cryptocurrency exchange FTX [5], Bitcoin and other cryptocurrencies were down almost 70 percent relative to the start of the year. However, their value remains significantly higher in comparison to 2020 levels, suggesting that ransomware groups will not disappear.

We posit that ransomware attacks will continue to rise as threat actors look to increase their victim list to make up for the staggering decline in the value of cryptocurrencies and the extreme market volatility. Simple economics suggests that threat actors would need to make up their shortfall in cryptocurrency value decline by either increasing the ransom pay-out rate (i.e., probability) or increasing the number of victims (i.e., supply). As organisations’ defenses become more advanced, cybercriminals may also need to shift to more sophisticated techniques to achieve initial access. In a recent incident response, we also observed the RaaS group Black Basta achieve initial access via a mass-scale phishing campaign before deploying ransomware (read more in a future blog post!). We expect more of the same in 2023.

The race for talent is on – threat actors are collaborating, crowdsourcing, and leveraging artificial intelligence (AI) to innovate. Enterprises will level the playing field by embracing “learn to hack” and “hack to earn” concept.

Threat actors have always been looking to gain a competitive advantage by specialising and crowdsourcing their skillsets. In 2022, our dark web monitoring allowed us to observe a 400 percent increase in listings of Initial Access Brokers (IABs), which are specialised cybercriminals that sells access to compromised networks. This outsourcing model allows other cybercriminals, such as affiliates of RaaS groups including BlackCat/ALPHV, to focus on their domain expertise (read more here). This demonstrates that this model was effective to a large extent.

However, talent has never been more scarce. Innovative threat actors have resorted to other channels for growth and inspiration. For example, other RaaS groups such as LockBit 3.0 RaaS group introduced the first bug bounty programme offered by cybercriminals. This included up to US$ 1 million for hackers of all backgrounds should they identify critical flaws in their malware, tools, or infrastructure. [6] Other threat actors have been observed from our dark web monitoring to host regular hackathons promising prize pools of up to one (1) Bitcoin for technology-specific POCs. Finally, the introduction of new tools such as ChatGPT has pushed the barrier to entry to a much lower level, and it has never been easier for script kiddies to weaponise their exploits.

We theorise that threat actors would further seek out various means to improve their competitive advantage, including collaboration and crowdsourcing. This was already an existing trend due to the RaaS affiliate model and attack-as-a-service models such as IABs, but is being disrupted by bug bounty programmes, hackathons, and artificial intelligence as a means to overcome the global cybersecurity talent shortage and skills gap. [7] As a result, enterprises are now facing an uphill battle against threat actors that are led by organisations that are harnessing the power of the people. To level the playing field, we also expect that enterprises will explore how to embrace the “learn to hack” and “hack to earn” concepts. We posit that leading enterprises will participate in bug bounty programmes and shift away from regular vulnerability scans and penetration testing to continuous assessment by bounty hunters who may not be affiliated with any vendor. Meanwhile, we also expect to see the establishment of cyber academies with the intention of democratising security through the re-skilling and upskilling pf all interested individuals regardless of their technical background. This would also provide enterprises with a new talent pipeline to ensure we have sufficient resources to fight back against “cybercriminalism”.

Web-based exploitation and targeting of individual consumers will follow-up on the hype of metaverse and the web3 ecosystem

The metaverse has quickly gone from concept to working reality in the past years. A lot of talk in 2022 was focused on simulating physical operations on the metaverse activities through games, virtual experiences or shopping with cryptocurrency and other digital assets. These experiences are underpinned by technologies such as virtual reality (VR), augmented reality (AR) devices, and artificial intelligence (AI), which naturally introduce new risks and accentuates old ones due to interoperable platforms in web3. [8] In particular, phishing email and messaging scams are already successfully leveraged by threat actors to steal passwords, private keys, personal information and money. In the metaverse, that could be even easier, especially if people think they are speaking to the physical representation of somebody they know and trust, when it could be someone else entirely. [9]

We posit that 2023 would be the year where threat actors, in particular cybercriminals, make a large jump towards targeting both businesses and individual consumers, with an increased focus to exploit web-based vulnerabilities for initial access as a result of the growing connectivity and digitalisation. We had already observed this uprising trend in late 2022 with large-scale global smishing campaigns targeting Hong Kong and Singapore citizens by masquerading as trusted and reputable locally-based public and private postal service providers (read more here). The metaverse and web3 exacerbates consumer-targeting and introduces new vulnerabilities to an increased attack surface. Aside from smart contract weaknesses, further web-application based vulnerabilities such as Spring4Shell (CVE-2022-22965) is expected to be discovered, weaponised, and utilised by threat actors to deploy cryptocurrency miners. [10] PwC’s Dark Lab had uncovered the Spring4Shell POC on the dark web two days prior to the disclosure of the zero-day vulnerability (read more here), which further emphasises on the notion that the rate of weaponisation continues to accelerate from weeks to days or even hours.

Recommendations to Secure Your 2023

There is no telling with certainty what 2023 holds, but our experience with the challenges of 2022 teach us a number of valuable lessons on how organisations can harden their cyber security posture to protect against a multitude of attack vectors.

  • Grow selective hands-on technical capabilities in-house, and look to outsource and crowdsource your organisation’s security –
    • Get started with bug bounty programmes: organisations should look to emulate threat actors’ by crowdsourcing specific parts of their security initiatives. In particular, organisations should explore onboarding to bug bounty programmes as it leverages the competitive advantage of the community to identify potential vulnerabilities and misconfigurations rapidly and continuously in their external perimeter. This would level the playing field, and ensure that enterprises are not alone in facing threats from threat actors groups and their affiliates by themselves. If this route were pursued, organisations should ensure they have proper governance and processes (e.g., Vulnerability Disclosure Policy) to ensure responsible disclosure of potential vulnerabilities by bounty hunters.
    • Upskill and reskill your current workforce’s technical capabilities: organisations should not just rely on purely outsourcing security tasks, given there is a global shortage of talent. Instead, they should look for practical hands-on technical courses that would upskill and/or reskill their existing workforce to be more proficient in cyber threat operations, including but not limited to offensive security, security operations, incident response, threat intelligence, and threat and vulnerability management.
  • Enforce a Layered Intrusion Defense Strategy
    • Continuously Discover and Harden Your Attack Surface: organisations should prioritise efforts to evaluate their attack surface exposure by reviewing public-facing services and technologies in order to assess the potential risks of internet-facing services and making necessary countermeasures to eliminate the risk, such as reducing internet-exposed infrastructure, network segmentation, or decoupling the demilitarised zone from the internal network.
    • Protect Privileged Accounts: as we observe threat actors pivot targeting to end users, it is critical to enforce strong credential protection and management strategies and solutions to limit credential theft and abuse. This includes leveraging technologies such as account tiering and managed services accounts, enforcing multi-factor authentication (MFA), credential hardening from privileged accounts, and regular reviewing of access rights ensuring that all practices align with zero trust and least privilege policies.
    • Review and Strengthen Email Security: review current email solution configurations to ensure coverage from preventative security solutions (including external firewalls and web proxies) and implementation of conditional access rules to restrict access of suspicious activity. Consider hardening email security by leveraging artificial intelligence and machine learning technologies to augment the authentication process and create an additional barrier to restrict potential threats from bypassing detecting and delivering to the victim.
    • Identifying and Protecting Critical Internal Systems: threat actors target critical systems (i.e. Domain Controllers, local and cloud backup servers, file servers, antivirus servers) that house highly sensitive information, which observed in various incidents were not protected by EDR solutions. It is crucial that organisations secure critical systems by enforcing heightened approach to devising security strategies for critical assets – including EDR, stringent patching standards, network segmentation and regular monitoring for anomolies and/or indicators of compromise.
    • Defending Against Lateral Movement: the majority of threat actors moving across network rely on mechanisms that are relatively easy to disrupt with security restrictions such as restriction of remote desktop protocol between user zones, network zoning for legacy systems, segmenting dedicated applications with limited users, and disabling Windows Remote Management, among others.
  • Continuously Assess your Attack Surface Exposure to understand what threats present the most prevalent challenges to your organisations and uplift preventive and detective strategies to protect against likely threats.
    • Establish a robust attack surface management programme to continuously identify potential vulnerabilities on your public-facing applications, discover potential shadow IT, and stay alert to potential security risks as a result of the changing threat landscape (e.g., newly registered domains that may look to impersonate your organisation). External-facing assets should be protected with the relevant security solutions and policies to prevent, detect, and restrict malicious activity, as well as to facilitate rapid response and recovery in the case of a breach.
    • Perform threat modelling to identify the threat actor groups most likely to target your region and/or sector, map your attack surface to the identified potential threats to assess how a threat actor could exploit your attack surface, and develop a plan of action to minimise that threat exposure. Regardless of whether there was a breach or not, we also recommend organisations conduct iterative intelligence-led threat hunting using the outputs of the threat modelling. As a result, the threat model also needs to be updated on a regular basis (i.e., several times a year, if not already continuously).
    • Establish continuous dark web monitoring to discover if there are data breaches related to your organisation, as well as if threat actors such as IABs looking to sell access to compromised accounts and breached external assets such as web applications and web servers.
  • Adopt a ‘Shift Left’ Mindset – embed cybersecurity at the forefront of innovation and implementation of new platforms, products, as well as the adoption of cloud or software solutions.
    • DevSecOps: embedding cybersecurity considerations from the initial development stage enables developers to identify and address bugs and security challenges early in the development progress, strengthening the security posture of the platform to reduce vulnerabilities and attack surface exposure.
    • Adoption of new technologies: the shift left mindset can also be applied to the adoption of cloud, security, and other software solutions. Organisations should be maintain oversight and awareness of new technologies being deployed in their network, assess the scope and coverage of the solutions, and subsequently develop a process to assess the security implications and risks of using these technologies.

Further information

Feel free to contact us at [darklab dot cti at hk dot pwc dot com] for any further information.

Technical analysis of LockBit 2.0 affiliates’ SonicWall exploit that bypasses MFA  

Posted on by darklabhk

We outline the tactics, techniques and procedures of the threat actor, and share the technical details of the indicators of compromise for one of our incident response experiences in 1H2022.

In the previous blog post, we reported on the novel technique leveraged by LockBit 2.0 affiliates to  exploit SonicWall Secure Remote Access (SRA) Secure Sockets Layer Virtual Private Network (SSL VPN) appliance to retrieve the time-based one-time password (TOTP) which enabled the circumvention of the multi-factor authentication (MFA) access control. We identified at the point in time from open source internet search engines that over one hundred Hong Kong and Macau organisations may be susceptible to this exploit based on their reported use of potentially vulnerable appliances.

We follow-up on that blog post with a technical analysis that outlines the LockBit 2.0 affiliates’ Tactics, Techniques and Procedures (TTPs) as observed in our incident response experiences. In addition, we set the scene for our final blog post which will explore the potential factors that enables the LockBit Ransomware-as-a-Service (RaaS) group to continue innovating at a rapid pace and cement their position as a major player in the ransomware threat landscape.

Analysis and Exploitation in the wild

Reconnaissance

We observed through analysis on the SSLVPN appliance and firewall network traffic logs that either CVE-2019-7481 or CVE-2021-20028 was exploited twice prior to initial access. The first recorded instance was in late 2021, in which the affiliate obtained the credentials of an administrative account. We conclude this with high confidence given this credential had not been leaked via data breaches or to the Dark Web previously, while the user had adopted a strong password given its length and use of four password complexity character classes.

Over the next three months, each login attempt originated from a unique external IP address and were unsuccessful due to the enforcement of MFA. The exploit was executed again prior to successful initial access, again from a different IP address. The use of a different external IP address each time spread over a sporadic timeframe is a strong indication of likely malicious intent by a threat actor that sought to remain stealthy to avoid detection and triggering of the victim’s incident response protocols.

The list of known malicious IP addresses are listed below, and we posit with high confidence they are utilised by the same threat actor for the following reasons:

  • 91.219.212[.]214 – the first observed exploiting an SQLi vulnerability. This IP address has been reported multiple times as malicious from reputable sources to have conducted suspicious malicious activities, including spam, brute-forcing, web application abuse, and vulnerability exploitation.[1] 
  • 5.206.224[.]246 – the first unsuccessful attempt to login as an administrative user, suggesting that this IP address is associated with 91.219.212[.]214 to obtain and utilise the strong and complex password.
  • 51.91.221[.]111 – which resolves to 213.186.33[.]5 and has been flagged by the security community to be malicious and has served as a command-and-control infrastructure, i.e., Cobalt Strike server.[2]
  • 194.195.91[.]29 – the second observed exploitation of the SQLi vulnerability, with the subsequent login attempt being successful, indicating that the threat actor likely had chained it with the undisclosed zero-day vulnerability.

Initial Access

The threat actor gained access to the victim network by chaining an SQLi vulnerability – one of CVE-2019-7481 or CVE-2021-20028 – with an undisclosed zero-day vulnerability to circumvent the MFA access control of the victim’s SonicWall SRA SSLVPN. Details of the vulnerability chaining are illustrated in the below diagram.

Figure 1 – Holistic vulnerability chaining of SQLi vulnerability with undisclosed post-authentication zero-day vulnerability

Through our systematic method for discovering and analysing attack paths, we were able to replicate the exploited zero-day vulnerability performed by the threat actor. A summary of the undisclosed post-authentication local file inclusion zero-day vulnerability is provided below:

CVE(s)CVE-2022-22279
First Published Date11 March 2022
CVSS v34.9
Affected VersionsSonicWall SMA100 version 9.0.0.9-26sv and earlier.[3]
DescriptionPost-authentication vulnerability that enables threat actors to download the persist.db database on their local device by targeting endpoint’s /cgi-bin/sslvpnclient. extract valid user credentials from the settings.json file, including the username, encrypted passwords, and the TOTP.[4]
Potential ImpactSensitive information disclosure that enables threat actors to circumvent the MFA access control to impersonate valid users and obtain initial access to the victim’s network.
Proof of Concept (PoC) AvailableAt the time of writing, there were no publicly available PoCs identified. DarkLab reported the security vulnerability along with their PoC exploit code to SonicWall’s Product Security Incident Response Team (PSIRT), and on 12 April 2022 observed the release of the advisory acknowledging the vulnerability which we had disclosed.
Exploited in the WildAt the time of writing, this vulnerability is not known to be exploited in the wild.
Patch AvailableNo
Workaround AvailableNo

However, the threat actor required valid user credentials to exploit the post-authentication zero-day vulnerability. Based on this requirement and the victim’s firmware, we identified to two pre-authentication SQLi vulnerabilities – CVE-2019-7841 and CVE-2021-20028 – that the threat actor may have leveraged to obtain a valid session. A summary of these vulnerabilities are provided below:

CVE(s)CVE-2019-7841
First Published Date18 December 2019
CVSS v37.5
Affected VersionsPer SonicWall’s PSIRT, SMA100 version 9.0.0.3 and earlier.[5] However, we noted from a cybersecurity consultancy firm that devices with version 9.0.0.5 firmware and earlier were still vulnerable.[6]
DescriptionPre-authentication SQLi vulnerability in the customerTID parameter which can be exploited remotely. Successful exploitation would allow the threat actor to list active session identifiers for authenticated users in a table named Sessions.[7]
Potential ImpactSensitive information disclosure and initial access under the right conditions (i.e., no MFA access control).
Proof of Concept (PoC) AvailableAt the time of writing, there were no publicly available PoCs identified. However, security researchers have reportedly reproduced the exploit based on samples obtained from in-the-wild exploitation.[8]
Exploited in the WildThis vulnerability has been actively exploited in the wild reportedly since 8 June 2021.[9] SonicWall’s PSIRT published a notification on 13 July 2021 detailing an incident leveraging this vulnerability to perform a targeted ransomware attack.[10]
Patch AvailableYes for organisations running 9.x firmware. No for organisations running unpatched and end-of-life (EOL) 8.x firmware.[11]
Workaround AvailableNo
CVE(s)CVE-2021-20028
First Published Date14 July 2021
CVSS v39.8
Affected VersionsSonicWall SRA appliances running all 8.x firmware, an old version of firmware 9.x (9.0.0.9-26sv or earlier), or version 10.2.0.7.[12] However, we noted from a cybersecurity consultancy firm that devices with version 10.x firmware were potentially vulnerable.[13]
DescriptionPre-authentication SQLi vulnerability in the customerTID parameter which can be exploited remotely. Successful exploitation would allow the threat actor to list active session identifiers for authenticated users in a table named Sessions.[14]
Potential ImpactSensitive information disclosure and initial access under the right conditions (i.e., no MFA access control).
Proof of Concept (PoC) AvailablePer Twitter trails, we understand that the PoC was leaked on paste bins[15] by an alleged DarkSide and LockBit affiliate that goes by the name “Wazawaka” on 25 January 2022.[16] While the leak site is now inaccessible, we noted that security researchers have reportedly reproduced the exploit. [17], [18], and [19]
Exploited in the WildNo known mass exploitation in the wild.
Patch AvailableYes for organisations running 9.x firmware. No for organisations running unpatched and end-of-life (EOL) 8.x firmware.[20]
Workaround AvailableNo

Establishing Persistence

Upon login via the built-in SonicWall SRA SSLVPN administrative account, the threat actor did not require to perform privilege escalation as the threat actor obtained an account which, under the configurations at the time, was integrated with the victim’s Active Directory, and had been assigned domain administrator privileges. Thus, the threat actor cemented their position was to create an Active Directory account “audit” with similar privileges, and proceeded to perform the majority of subsequent malicious activities by leveraging this user.

Discovery

The threat actor transferred the SoftPerfect Network Scanner tool, which is a publicly available network scanner used to discover hostnames and network services, via various network protocols such as Hypertext Transfer Protocol (HTTP), Windows Management Instrumentation (WMI), Simple Network Management Protocol (SNMP), and Secure Shell (SSH).[21] The threat actor was able to launch the scanner to map out the internal network topology and identify additional critical systems.

Filenamenetscan.exe
SHA-256a710f573f73c163d54c95b4175706329db3ed89cd9337c583d0bb24b6a384789
File typeWin32 EXE
File size16,539,648 bytes

Lateral Movement

Subsequent to identifying the critical systems such as backup servers and the management information system, the threat actor leveraged the stolen administrative account as well as the created account “audit” to initiate a Remote Desktop Connection to access those endpoints.

Defense Evasion

The kavremover tool was staged and executed to disable the endpoint anti-virus solution Kaspersky on the critical systems.[22] This helped to set up the next stage of the campaign, which focuses on the exfiltration of victim data that will later be used for ransom.

Filenamekavremvr.exe
SHA-256c230e6a2a4f4ac182ba04fee875f722a2c9690cb5d678acd5e40a72d5ec1f275
File typeWin32 EXE
File size14,143,976 bytes

In addition, the executable file YDArk.exe was located on selected endpoints. This open source tool was first observed in the wild on 11 June 2020[23], with the commit available on GitHub for download.[24] From public sources, we note that it is a multi-purpose toolkit offered with English and Chinese modules that allow the threat actor to evade defenses through various techniques, including process injection and rootkit.[25] As a result, we posit this tool was downloaded with the intention of disabling the anti-virus solution such as Windows Defender, alongside the kavremover tool.

Exfiltration and Extortion

Initially, the threat actor makes it known to the target network that it has encrypted the network by leaving a ransom note on the impacted systems. In some cases, LockBit affiliates have been observed to stage hacking tools and to exfiltrate data to cloud storage platforms such as AnonFiles that enables users to anonymously access and share contents.[26] and [27]  

Exfiltration and Extortion

Ransomware deployment was observed to have been done manually, with the threat actors executing on the critical servers. Following the execution of Lockbit 2.0, threat actors typically move onto the extortion phase of the campaign, which is broken down into two stages; initial ransom note, and leak website.

FilenameLockBit_9C11F98C309ECD01.exe
SHA-256822b0d7dbf3bd201d6689e19b325b3982356c05bc425578db9aa4ce653deaaa7
File typeWin32 EXE
File size982,528 bytes

We provide a sample of the Lockbit 2.0 ransomware and several behaviours observed in our incident from available logs.

  • The ransomware enumerated connected drives and read the root path of hard drives other than the default C: drive and discovered additional drives connected to the infected system that the ransomware was able to propagate to and encrypt.
  • The ransomware deleted the Volume Shadow Copy Server (VSS), likely by running the following command:
    • C:\Windows\System32\cmd.exe /c vssadmin delete shadows /all /quiet & wmic shadowcopy delete & bcdedit /set {default} bootstatuspolicy ignoreallfailures & bcdedit /set {default} recoveryenabled no & wbadmin delete catalog -quiet
  • Successfully encrypted files from Lockbit 2.0 had their file extension changed to .lockbit. Unlike typical cases, we did not observe the user background being modified using the \REGISTRY\USER\Control Panel\Desktop\Wallpaper registry

Finally, we observed that all the Active Directory accounts were disabled by the threat actor subsequent to the execution of Lockbit 2.0. In performing this action, legitimate users (e.g., administrators) were inhibited access to accounts, thereby delaying the actions that could be taken to restore the impacted systems and network.

Conclusion

Lockbit 2.0 affiliates work on behalf of the Lockbit group to conduct ransomware campaigns against organisations and industries across the globe. The affiliates’ abilities to conduct the intrusion and execution of Lockbit 2.0 ransomware vary, and through these incidents we observed affiliates with a diversified capability and skillset exploit a known SQLi vulnerability in a novel way to circumvent the MFA access control and obtain initial access. Organisations are encouraged to review the TTPs leveraged by LockBit affiliates as a result of our recent incident response experience to improve their preventive and detective controls.

Recommendations

As mentioned in the previous blog post, defending against undisclosed exploits are extremely challenging, but not impossible if organisations adopt a defense-in-depth approach. The following guiding principles should be observed, atop of those already listed in the previous blog post:

  • Implement a robust threat and vulnerability management programme that leverages cyber threat intelligence to achieve a resilient security posture. Specifically, to maintain an inventory of assets, with clear indication of the critical systems and sensitive data, mapped to business owners and the relevant security controls to manage cyber risk.
  • Design, implement, and operate an enterprise security architecture that embeds the concept of zero trust to focus on protecting critical resources (assets, services, workflows, network accounts, etc.), and not specifically just for network segments, as the network location is no longer seen as the prime component to the security posture of the resource.
  • Segment networks where operationally practical to prevent the spread of ransomware by controlling traffic flows between various subnetworks and by restricting adversary lateral movement. Disable unused administrative ports internally, such as Remote Desktop Protocol (RDP).
  • Identify, detect, and investigate abnormal activity and potential traversal of the threat actor across the network, such as through deployment of Endpoint Detection and Response (EDR) tools on critical endpoints, including workstations, laptops and servers.

In addition, we strongly urge organisations that have deployed the vulnerable versions of SonicWall SRA SSLVPN to execute the remediation actions outlined in the previous blog post, if not already completed.  Details can be found here.

MITRE ATT&CK TTPs Leveraged

We include the observed MITRE ATT&CK tactics and techniques elaborated from the incident.

  • Reconnaissance: Active Scanning – Vulnerability Scanning (T1595.002)
  • Reconnaissance: Gather Victim Network Information – IP Addresses (T1590.005)
  • Initial Access: Exploit Public-Facing Application (T1190)
  • Initial Access: Valid Accounts (T1078)
  • Persistence: Account Manipulation (T1098)
  • Persistence: Create Account: Domain Account (T1136.002)
  • Privilege Escalation: Domain Accounts (T1078.002)
  • Defense Evasion: Impair Defenses: Disable or Modify Tools (T1562.001)
  • Defense Evasion: Indicator Removal on Host: File Deletion (T1070.004)
  • Credential Access: Credentials from Password Stores (T1555)
  • Discovery: Network Service Scanning (T1046)
  • Discovery: File and Directory Discovery (T1083)
  • Discovery: Remote System Discovery (T1018)
  • Lateral Movement: Remote Services: Remote Desktop Protocol (T1021.001)
  • Collection: Data from Local System (T1533)
  • Command and Control: Remote File Copy (T1544)
  • Impact: Account Access Removal (T1531)
  • Impact: Data Encrypted for Impact (T1486)
  • Impact: Inhibit System Recovery (T1490)

Indicators of Compromise (IoCs)

We include the observed IoCs elaborated from part one of the blogpost. We will expand this list as we deep-dive into the affiliates’ TTPs as observed from our incident response experience in Q1 2022.

IndicatorType
c230e6a2a4f4ac182ba04fee875f722a2c9690cb5d678acd5e40a72d5ec1f275SHA-256
a710f573f73c163d54c95b4175706329db3ed89cd9337c583d0bb24b6a384789SHA-256
49bac09d18e35c58180ff08faa95d61f60a22fbb4186c6e8873c72f669713c8cSHA-256
822b0d7dbf3bd201d6689e19b325b3982356c05bc425578db9aa4ce653deaaa7SHA-256
91.219.212[.]214IPv4 Address
5.206.224[.]246IPv4 Address
51.91.221[.]111IPv4 Address
213.186.33[.]5IPv4 Address
194.195.91[.]29IPv4 Address
kavremvr.exeExecutable File
netscan.exeExecutable File
LockBit_9C11F98C309ECD01.exeExecutable File
YDArk.exeExecutable File
.lockbitEncrypted Files Extension
Restore-My-Files[.]txtFilename

Feel free to contact us at [darklab dot cti at hk dot pwc dot com] for any further information.

LockBit 2.0 affiliate’s new SonicWall exploit bypasses MFA

Posted on by darklabhk

Increasing Capabilities of LockBit 2.0 Gang Per Our Incident Response Experience in Q1 2022 Impacts Over One Hundred Hong Kong and Macau Organisations; Exploit Acknowledged by SonicWall as CVE-2022-22279

In the first quarter of 2022, DarkLab responded to several ransomware incidents impacting organisations in the financial services, real estate, and manufacturing sectors across Hong Kong, China and Asia Pacific. In all such incidents, the presence of the LockBit executable file, .lockbit extension files, and the StealBit malware suggests that affiliates of the cybercriminal group that operates the LockBit 2.0 Ransomware-as-a-Service (RaaS) was likely behind the incidents.

LockBit 2.0 RaaS is a well-documented group with established tactics, techniques and procedures (TTPs) that has been active since 2019.[1] During our incident response investigations, we found LockBit affiliates exploiting two victims’ SonicWall Secure Remote Access (SRA) Secure Sockets Layer Virtual Private Network (SSLVPN) appliance to establish a foothold in their networks. In the first instance, the affiliate exploited a known SQL injection (SQLi) vulnerability to obtain valid usernames and passwords. Given the multi-factor authentication (MFA) access control was not enabled, they were able to achieve initial access relatively easily. In the second instance, the affiliate performed follow-up actions to retrieve the time-based one-time password (TOTP) which enabled the circumvention of the MFA access control.

In this blog post we will report on their novel technique to exploit SonicWall SSLVPN appliances and bypass MFA. According to results from open source internet search engines, over one hundred Hong Kong and Macau organisations may be susceptible to this exploit based on their reported use of potentially vulnerable appliances. This exploit disclosed by DarkLab has since been acknowledged by SonicWall as CVE-2022-22279.

A second blog post will then outline the LockBit affiliates’ TTPs as observed in our incident response experience. The final blog post will explore the potential factors that enables the LockBit RaaS group to continue innovating at a rapid pace and cement their position as a major player in the ransomware threat landscape.

Initial Access

The typical modus operandi of LockBit 2.0 affiliates is to gain access to a victim network by exploiting known vulnerabilities of public-facing services, including vulnerable SSLVPN. In particular, CVE-2018-13379 [2] has been the preferred vulnerability in many incidents, including those DarkLab responded to in January and February 2022. The vulnerability is several years old, and LockBit 2.0 affiliates were still able to capitalise on the exploit that allows for unauthenticated users to download system files through crafted HTTP resources requests. Other affiliates have been reported to gain initial access by conducting Remote Desktop Protocol (RDP) brute forcing[3] or through purchasing access to compromised servers via underground markets.[4]

However, in two incidents that DarkLab responded to in March 2022 we observed a new infection vector.  Affiliates were observed to exploit a known but relatively obscure SQLi vulnerability – either CVE-2019-7481 [5] or CVE-2021-20028 [6] – in a novel manner to retrieve user session data stored in the SonicWall SSLVPN appliance to the affiliate’s local endpoint. Retrieved data included valid usernames, passwords, and the TOTP. In doing so, the affiliates could circumvent the MFA access control, impersonate any user to gain initial access, and subsequently deploy ransomware.

Figure 1 – LockBit’s initial attack chain

The latter incidents we responded to in March 2022 were noteworthy for two reasons. First, LockBit affiliates were not reported to have exploited SonicWall SSLVPN products in the past. Second, this was the first publicly observed instance that the known SQLi vulnerability could be exploited by threat actors to extract the TOTP SHA-1 tokens of onboarded users. Affiliates could then generate the QR code containing the required information to generate one time passwords (OTP) in an authenticator app of their choice.[7] This proved to be an innovative way to circumvent the existing MFA access controls. The observation of the exploitation suggests the affiliates of LockBit now have additional tools in their arsenal, and indicates the importance they place in continuous improvement as the group looks to differentiate itself from competitors.

Impact to Hong Kong and Macau

DarkLab replicated and verified the novel exploitation method of the post-authentication vulnerability through internal testing of several known impacted SonicWall SSLVPN firmware. We have shared all relevant details, including the technical exploit code, with the SonicWall Product Security Incident Response Team (PSIRT) in March 2022 to ensure organisations are protected. We will not publicly disclose exact exploitation details to avoid replication by malicious actors.

Per subsequent communications with SonicWall PSIRT, we understood that the upgrades to SonicWall SMA firmware 10.2.0.7-34sv or above, and 9.0.0.10-28sv or above in February 2021 to address CVE-2021-20016 included comprehensive code-strengthening that proactively prevented malicious attackers from exploiting this vulnerability to circumvent the MFA access control.[8] On 12 April 2022, SonicWall PSIRT released the following advisory acknowledging the vulnerability CVE-2022-22279 which we had disclosed.[9]

As of the time of writing, we have not observed from our deep and dark web monitoring any specific intentions by threat actors to leverage this post-authentication vulnerability to target organisations in Hong Kong and Macau. However, we observed that Russian-speaking threat actors had been discussing this vulnerability in early February 2022, with posts from two underground forums – exploit[.]in and xss.[.]is – containing conversation details of purchasing the exploit code and outlining at a high-level the follow-up actions that can be taken to extract the TOTP from the active sessionid. 

Figure 2 – Screenshot of exploit[.]in underground forum
Figure 3 – Screenshot of xss[.]is underground forum

As a result of the LockBit incidents and various hacker chatter, we were concerned that local organisations may have missed SonicWall PSIRT’s advisory note; after all, we still observed compromises that resulted from the exploitation of CVE-2018-13379 on unpatched Fortinet SSLVPN appliances in February 2022. To that end, we conducted a passive, non-intrusive scan of both CVE-2019-7481 or CVE-2021-20028 on the full Internet Protocol address (IP address) range of Hong Kong and Macau. The preliminary results indicated that at least 100 organisations were vulnerable to CVE-2021-20028, with half of those also vulnerable to CVE-2019-7481.

DarkLab has since proactively contacted dozens of potentially affected organisations to alert them of the potential risks they faced. However, given there were a series of critical vulnerabilities pertaining to SonicWall SSLVPN appliances released in June 2021, it is likely that those may be exploited through other innovative methods by threat actors. For example, the Cybersecurity & Infrastructure Security Agency (CISA) listed CVE-2021-20016 as another SQLi vulnerability that allows a remote unauthenticated attacker to perform SQL query to access username password and other session related information in SMA100 build version 10.x. [10], which aligned with our communication with SonicWall’s PSIRT. We foresee that if left unpatched, this could pose a threat that adversaries may exploit to gain unauthorised access through exploitation of this vulnerability.

CVE NumberProductVulnerability NameDate Added to CatalogueShort Description
CVE-2021-20021SonicWall Email SecurityPrivilege Escalation Exploit Chain3 November 2021A vulnerability in version 10.0.9.x allows an attacker to create an administrative account by sending a crafted HTTP request to the remote host.
CVE-2021-20022SonicWall Email SecurityPrivilege Escalation Exploit Chain3 November 2021A vulnerability in version 10.0.9.x allows a post-authenticated attacker to upload an arbitrary file to the remote host.
CVE-2021-20023SonicWall Email SecurityPrivilege Escalation Exploit Chain3 November 2021A vulnerability in version 10.0.9.x allows a post-authenticated attacker to read an arbitrary file on the remote host.
CVE-2021-20016SonicWall SSLVPN SMA100SQL Injection Vulnerability3 November 2021A vulnerability in SMA100 build version 10.x allows a remote unauthenticated attacker to perform SQL query to access username, password and other session related information.
CVE-2021-20018SMA 100 AppliancesStack-Based Buffer Overflow Vulnerability28 January 2022SonicWall SMA 100 devices are vulnerable to an unauthenticated stack-based buffer overflow vulnerability where exploitation can result in code execution.
CVE-2021-20028SonicWall SRASQL Injection Vulnerability28 March 2022SRA products contain an improper neutralisation of a SQL Command leading to SQL injection.
Table 1 – CISA known exploited vulnerabilities catalogue listing various critical SonicWall CVEs that were being exploited in the wild as of 2 April 2022

The ongoing evolution of TTPs allowed LockBit’s affiliates to become the most prolific ransomware actors in 2022. Between 1 January and 31 March 2022, the group claimed 223 victims on their dark web leak site, compared to Conti’s 125. This equates to more than one-third of all known ransomware incidents for Q1 2022. To put it in another way, over the same period LockBit’s affiliates claimed almost 10 percent more victims than the other 24 known ransomware groups combined (223 compared to 164). LockBit’s reported activities have also increased over the course of the first three months of 2022. The gang claimed 112 victims in March, while it published details of 111 companies in the previous two months combined. This suggest an ongoing trend highlighting how LockBit will likely remain the most active ransomware-as-a-service offering for the coming months.

Figure 4 – Number of victims published on ransomware dark web leak sites between 1 January 2022 and 31 March 2022

Conclusion

Lockbit 2.0 affiliates work on behalf of the Lockbit group to conduct ransomware campaigns against organisations and industries across the globe. The affiliates’ abilities to conduct the intrusion and execution of Lockbit 2.0 ransomware vary, and through these incidents we observed affiliates with a diversified capability and skillset exploit a known SQLi vulnerability in a novel way to circumvent the MFA access control and obtain initial access. At least 100 organisations in Hong Kong and Macau are at potential immediate risk, and we foresee that if left unpatched, this could pose a threat that adversaries may exploit to gain unauthorised access through exploitation of this vulnerability. We will continue to monitor the situation and assist organisations as needed. In the next blog post, we will also share further details on the TTPs leveraged by LockBit affiliates as a result of our recent incident response experience with reference to the MITRE ATT&CK Framework, such that organisations can better prevent and detect malicious activities related to this RaaS group.

Recommendations

For organisations that have deployed the vulnerable versions of SonicWall SRA SSLVPN, we recommend the following actions immediately in the following order:

  • Upgrade legacy SRA SSLVPN device(s) running firmware 8.x given they are not supported by SonicWall; apply patches to the impacted versions of the 9.x or 10.x firmware.
  • Reset all user account Active Directory credentials that had previously authenticated via the SonicWall SRA SSLVPN. In particular, the Active Directory credentials that is tied to the SonicWall SRA device for authentication purpose should be changed.
  • Re-bind users’ second authentication factor (e.g., Google or Microsoft Authenticator) app with an updated TOTP, and ensure that users store their newly generated backup codes securely.[11]
  • Review the privileges granted to the Active Directory account tied to the SonicWall SRA device for user authentication purpose, and remove excess permissions where possible to adhere to the principle of least privilege. In general, Domain Administrator privilege should not be used.
  • Perform a review of access management with respect to identity and network access (e.g., removal of legacy and unused accounts, housekeeping of privileges for all accounts, and enforce network segmentation to tighten access to key servers).

Meanwhile, defending against undisclosed exploits are extremely challenging, but not impossible if organisations adopt a defense-in-depth approach. The following guiding principles should be observed:

  • Require multi-factor authentication for all services to the extent possible, especially on external remote services. 
  • Implement a robust threat and vulnerability management programme that leverages cyber threat intelligence to achieve a resilient security posture. Specifically:
    • Maintain regular cybersecurity patching hygiene practices, including a robust baseline that patched known exploited vulnerabilities and aims to reduce known attack surface. 
    • Leverage cyber threat intelligence to prioritise the remediation scale and timeline on a risk-based approach, through the incorporation of indications and warnings regarding trending threats per available proof-of-concept code, active exploitation by threat actors, and Darknet chatter.
  • Maintain “tertiary” offline backups (i.e., tertiary backup) that are encrypted and immutable (i.e., cannot be altered or deleted). This should be atop of your existing secondary data backups that should adopt security best practices, in particular network segmentation with your production and/or primary site.
  • Develop and regularly test the business continuity plan, ensuring that the entire backup, restoration and recovery lifecycle is drilled to ensure the organisation’s operations are not severely interrupted.

MITRE ATT&CK TTPs Leveraged

We include the observed MITRE ATT&CK tactics and techniques elaborated from part one of the blogpost. We will expand this list as we deep-dive into the affiliates’ TTPs as observed from our incident response experience in Q1 2022.

  • Initial Access: Exploit Public-Facing Application (T1190)
  • Initial Access: Valid Accounts (T1078)
  • Impact: Data Encrypted for Impact (T1486)

Indicators of Compromise (IoCs)

We include the observed IoCs elaborated from part one of the blogpost. We will expand this list as we deep-dive into the affiliates’ TTPs as observed from our incident response experience in Q1 2022.

IndicatorType
7fcb724c6f5c392525e287c0728dbeb0MD5
adead34f060586f85114cd5222e8b3a277d563bdSHA-1
822b0d7dbf3bd201d6689e19b325b3982356c05bc425578db9aa4ce653deaaa7SHA-256
LockBit_9C11F98C309ECD01.exeExecutable File
.lockbitEncrypted Files Extension
91.219.212[.]214IPv4 Address
5.206.224[.]246IPv4 Address
51.91.221[.]111IPv4 Address
213.186.33[.]5IPv4 Address
194.195.91[.]29IPv4 Address

Feel free to contact us at [darklab dot cti at hk dot pwc dot com] for any further information.