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Crypto
Inside the SOC
GitLab vulnerability exploit detected by AI
Darktrace has discovered a significant number of cases involving a successful exploit of GitLab servers — a common open source software used by developers. The vulnerability, tracked as CVE-2021-22205, allows an unauthenticated, remote attacker to execute arbitrary commands as the ‘git’ user, giving them full access to the repository, including deleting, modifying, and exfiltrating source code.
In each case discovered by Darktrace AI, attackers successfully exploited servers and ran crypto-mining malware. However, this vulnerability opens the door into a wider range of possibilities, including data exfiltration, ransomware, and supply chain attacks.
The flaw was fixed on April 14, 2021, but recent research has revealed that this vulnerability is still exploitable with over 30,000 GitLab servers remaining unpatched.
The vulnerability has affected customers in every corner of the world, with Darktrace customers in the US, EMEA and APAC all targeted. Affected industries include technology, transportation, and education.
Attack details
The cases detailed below generally follow the same pattern. First, user accounts with admin privileges are registered on a publicly accessible GitLab server belonging to an unnamed customer. This is followed by a remote execution of commands that grant the rogue accounts elevated permissions.
Figure 1: Multiple model breaches firing on an unusual data egress event on October 30, which resulted in a Proactive Threat Notification model breach.
After multiple model breaches on malicious EXE downloads and command and control (C2) activities with the TOR network, the organization received a Proactive Threat Notification (PTN) from Darktrace that immediately alerted them to the issue. This enabled the customer to remove the compromised device from the network.
The next day, Darktrace discovered cryptocurrency mining occurring on a compromised server that was communicating on a non-standard port. This triggered alerts to the customer through Darktrace’s Proactive Threat Notification service, immediately escalating the threat to their security team.
Figure 2: Multiple cryptocurrency mining model breaches from the same server firing on November 3.
The related breaches include scripts from rare external locations and rare endpoints (endpoints that have never been contacted by the breach devices in the past). Not surprisingly, the endpoints in question are crypto-mining pools.
It is important to note that this GitLab vulnerability represents only the initial attack vector, which could result in a number of scenarios. In the customer environment detailed above, crypto-mining has occurred; however, exploitation of this vulnerability could serve as the first stage of a more destructive ransomware attack, or result in stolen intellectual property.
Lastly, throughout the compromises identified across Darktrace’s customer base, it appears that the Interactsh tool was leveraged by the threat actors in the attack. Interactsh is an open-source tool for out of band data transfers and validation of security flaws, and it is commonly used by both researchers and hackers. Darktrace was easily able to identify this tool as part of the larger threat.
Cyber AI Analyst investigates
Darktrace’s Cyber AI Analyst launched an immediate investigation, stitching together different events across a five-day period and revealing four stages of the attack. This presented the security team with all the information they needed to perform effective investigation and clean up, including isolating the infected devices.
Figure 3: Cyber AI Analyst automatically investigates, piecing together the events into a single narrative.
In another customer environment, Cyber AI Analyst was again able to piece together multiple security events to present a coherent security narrative, determining that the suspicious file downloads likely contained malicious software, and recommending immediate attention from security staff.
Figure 4: In a different case, Cyber AI Analyst surfaces a summary and key metrics around the suspicious file downloads.
Cyber AI Analyst made stellar detections and Proactive Threat Notification alerted affected clients ASAP. Clients were then supported through Ask the Expert (ATE) services. There has been no evidence of ransomware thus far, but these types of attacks typically gain a foothold on Internet-exposed servers and then pivot internally to deploy ransomware.
In a third example with a separate customer, Cyber AI Analyst stitched together six different security events into a single security narrative. Here, Darktrace’s technology was able to connect the dots between C2 behavior, suspicious file downloads, unusual connections, and Tor activity, eventually leading to its discovery of cryptocurrency mining.
Cyber AI Analyst specifically identified GitLab in the suspicious file downloads from a rare external endpoint. The fact that Darktrace was able to identify this in the context of a holistic view of threatening activity across this organization’s digital ecosystem — stretching from suspicious SSL connections to the eventual crypto-mining activity — presents a remarkable picture of Cyber AI Analyst in action.
Figure 5: Cyber AI Analyst identifying the GitLab activity in the context of the wider security narrative.
Concluding thoughts
Though the patch was released in April, over 50% of deployments remain unpatched. There are potential reasons why they remain unpatched — overworked security staff, or simply negligence.
Even when CVEs are mapped and patched promptly, however, novel and never-before-seen attacks can still slip through the cracks. Before the Gitlab flaw was publicly disclosed and fixed, this vulnerability was a zero-day.
And so, rather than wait for CVEs to be publicly disclosed, organizations would be prudent to adopt technologies that can detect and respond to emerging attacks at their earliest stages — regardless of whether they are exploiting known or unknown vulnerabilities.
At Darktrace we talk a lot about the problems novel and unknown threats pose for traditional security solutions. This case shows that even when a threat is known for over six months, difficulties in implementing and rolling out patching mean it can still cause issues.
Thanks to Darktrace’s AI continuously monitoring the behavior of our customer’s devices, they were able to identify the threat at its earliest stages, before it could develop into something more disruptive like ransomware. And had the customers had Darktrace Antigena configured, the technology would have responded autonomously to contain the malicious behavior before the attackers could get past stage one.
Thanks to Darktrace analyst Waseem Akhter for his insights on the above threat find.
Learn more about Darktrace’s Self-Learning AI
Technical details
Proactive Threat Notification model detections:
- Compromise / Anomalous File then Tor
- Compromise / High Priority Crypto Currency Mining
- Device / Initial Breach Chain Compromise
- Device / Large Number of Model Breaches from Critical Network Device
- Unusual Activity / Enhanced Unusual External Data Transfer
Other Darktrace model detections:
- Anomalous Connection / Anomalous SSL without SNI to New External
- Anomalous Connection / Application Protocol on Uncommon Port
- Anomalous Connection / Callback on Web Facing Device
- Anomalous Connection / Data Sent to Rare Domain
- Anomalous Connection / New User Agent to IP Without Hostname
- Anomalous Connection / Posting HTTP to IP Without Hostname
- Anomalous File / Multiple EXE from Rare External Locations
- Anomalous File / Internet Facing System File Download
- Anomalous File / Script from Rare Location
- Anomalous Server Activity / Outgoing from Serve
- Compromise / Beaconing Activity To External Rare
- Compliance / Crypto Currency Mining Activity
- Compromise / High Volume of Connections with Beacon Score
- Compromise / Large DNS Volume for Suspicious Domain
- Compromise / Monero Mining
- Compliance / Possible Tor Usage
- Device / Internet Facing Device with High Priority Alert
- Device / Large Number of Model Breaches
- Device / Large Number of Connections to New Endpoints
- Device / Suspicious Domain
- Unusual Activity / Unusual External Data to New IPs
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Inside the SOC
How Abuse of ‘PerfectData Software’ May Create a Perfect Storm: An Emerging Trend in Account Takeovers
Amidst the ever-changing threat landscape, new tactics, techniques, and procedures (TTPs) seem to emerge daily, creating extreme challenges for security teams. The broad range of attack methods utilized by attackers seems to present an insurmountable problem: how do you defend against a playbook that does not yet exist?
Faced with the growing number of novel and uncommon attack methods, it is essential for organizations to adopt a security solution able to detect threats based on their anomalies, rather than relying on threat intelligence alone.
In March 2023, Darktrace observed an emerging trend in the use of an application known as ‘PerfectData Software’ for probable malicious purposes in several Microsoft 365 account takeovers.
Using its anomaly-based detection, Darktrace DETECT™ was able to identify the activity chain surrounding the use of this application, potentially uncovering a novel piece of threat actor tradecraft in the process.
Microsoft 365 Intrusions
In recent years, Microsoft’s Software-as-a-Service (SaaS) suite, Microsoft 365, along with its built-in identity and access management (IAM) service, Azure Active Directory (Azure AD), have been heavily targeted by threat actors due to their near-ubiquitous usage across industries. Four out of every five Fortune 500 companies, for example, use Microsoft 365 services [1].
Malicious actors typically gain entry to organizations’ Microsoft 365 environments by abusing either stolen account credentials or stolen session cookies [2]. Once inside, actors can access sensitive data within mailboxes or SharePoint repositories, and send out emails or Teams messages. This activity can often result in serious financial harm, especially in cases where the malicious actor’s end-goal is to elicit fraudulent transactions.
Darktrace regularly observes malicious actors behaving in predictable ways once they gain access to customer Microsoft 365 environment. One typical example is the creation of new inbox rules and sending deceitful emails intended to convince recipients to carry out subsequent actions, such as following a malicious link or providing sensitive information. It is also common for actors to register new applications in Azure AD so that they can be used to conduct follow-up activities, like mass-mailing or data theft. The registration of applications in Azure AD therefore seems to be a relatively predictable threat actor behavior [3][4]. Darktrace DETECT understands that unusual application registrations in Azure AD may constitute a deviation in expected behavior, and therefore a possible indicator of account compromise.
These registrations of applications in Azure AD are evidenced by creations of, as well as assignments of permissions to, Service Principals in Azure AD. Darktrace has detected a growing trend in actors creating and assigning permissions to a Service Principal named ‘PerfectData Software’. Further investigation of this Azure AD activity revealed it to be part of an ongoing account takeover.
‘PerfectData Software’ Activity
Darktrace observed variations of the following pattern of activity relating to an application named ‘PerfectData Software’ within its customer base:
- Actor signs in to a Microsoft 365 account from an endpoint associated with a Virtual Private Server (VPS) or Virtual Private Network (VPN) service
- Actor registers an application called 'PerfectData Software' with Azure AD, and then grants permissions to the application
- Actor accesses mailbox data and creates inbox rule
In two separate incidents, malicious actors were observed conducting their activities from endpoints associated with VPN services (HideMyAss (HMA) VPN and Surfshark VPN, respectively) and from endpoints within the Autonomous System AS396073 MAJESTIC-HOSTING-01.
In March 2023, Darktrace observed a malicious actor signing in to a Microsoft 365 account from a Kuwait-based IP address within the Autonomous System, AS198605 AVAST Software s.r.o. This IP address is associated with the VPN service, HMA VPN. Over the next couple of days, an actor (likely the same malicious actor) signed in to the account several more times from two different Nigeria-based endpoints, as well as a VPS-related endpoint and a HMA VPN endpoint.
During their login sessions, the actor performed a variety of actions. First, they created and assigned permissions to a Service Principal named ‘PerfectData Software’. This Service Principal creation represents the registration of an application called ‘PerfectData Software’ in Azure AD. Although the reason for registering this application is unclear, within a few days the actor registered and granted permission to another application, ‘Newsletter Software Supermailer’, and created a new inbox rule names ‘s’ on the mailbox of the hijacked account. This inbox rule moved emails meeting certain conditions to a folder named ‘RSS Subscription. The ‘Newsletter Software Supermailer’ application was likely registered by the actor to facilitate mass-mailing activity.
Immediately after these actions, Darktrace detected the actor sending out thousands of malicious emails from the account. The emails included an attachment named ‘Credit Transfer Copy.html’, which contained a suspicious link. Further investigation revealed that the customer’s network had received several fake invoice emails prior to this initial intrusion activity. Additionally, there was an unusually high volume of failed logins to the compromised account around the time of the initial access.
In a separate case also observed by Darktrace in March 2023, a malicious actor was observed signing in to a Microsoft 365 account from an endpoint within the Autonomous System, AS397086 LAYER-HOST-HOUSTON. The endpoint appears to be related to the VPN service, Surfshark VPN. This login was followed by several failed and successful logins from a VPS-related within the Autonomous System, AS396073 MAJESTIC-HOSTING-01. The actor was then seen registering and assigning permissions to an application called ‘PerfectData Software’. As with the previous example, the motives for this registration are unclear. The actor proceeded to log in several more times from a Surfshark VPN endpoint, however, they were not observed carrying out any further suspicious activity.
It was not clear in either of these examples, nor in fact any of cases observed by Darktrace, why actors had registered and assigned permissions to an application called ‘PerfectData Software’, and there do not appear to be any open-source intelligence (OSINT) resources or online literature related to the malicious usage of an application by that name. That said, there are several websites which appear to provide email migration and data recovery/backup tools under the moniker ‘PerfectData Software’.
It is unclear whether the use of ‘PerfectData Software’ by malicious actors observed on the networks of Darktrace customers was one of these tools. However, given the nature of the tools, it is possible that the actors intended to use them to facilitate the exfiltration of email data from compromises mailboxes.
If the legitimate software ‘PerfectData’ is the application in question in these incidents, it is likely being purchased and misused by attackers for malicious purposes. It is also possible the application referenced in the incidents is a spoof of the legitimate ‘PerfectData’ software designed to masquerade a malicious application as legitimate.
Darktrace Coverage
Cases of ‘PerfectData Software’ activity chains detected by Darktrace typically began with an actor signing into an internal user’s Microsoft 365 account from a VPN or VPS-related endpoint. These login events, along with the suspicious email and/or brute-force activity which preceded them, caused the following DETECT models to breach:
- SaaS / Access / Unusual External Source for SaaS Credential Use
- SaaS / Access / Suspicious Login Attempt
- SaaS / Compromise / Login From Rare Following Suspicious Login Attempt(s)
- SaaS / Email Nexus / Unusual Location for SaaS and Email Activity
Subsequent activities, including inbox rule creations, registration of applications in Azure AD, and mass-mailing activity, resulted in breaches of the following DETECT models.
- SaaS / Admin / OAuth Permission Grant
- SaaS / Compromise / Unusual Logic Following OAuth Grant
- SaaS / Admin / New Application Service Principal
- IaaS / Admin / Azure Application Administration Activities
- SaaS / Compliance / New Email Rule
- SaaS / Compromise / Unusual Login and New Email Rule
- SaaS / Email Nexus / Suspicious Internal Exchange Activity
- SaaS / Email Nexus / Possible Outbound Email Spam
- SaaS / Compromise / Unusual Login and Outbound Email Spam
- SaaS / Compromise / Suspicious Login and Suspicious Outbound Email(s)
In cases where Darktrace RESPOND™ was enabled in autonomous response mode, ‘PerfectData Software’ activity chains resulted in breaches of the following RESPOND models:
• Antigena / SaaS / Antigena Suspicious SaaS Activity Block
• Antigena / SaaS / Antigena Significant Compliance Activity Block
In response to these model breaches, Darktrace RESPOND took immediate action, performing aggressive, inhibitive actions, such as forcing the actor to log out of the SaaS platform, and disabling the user entirely. When applied autonomously, these RESPOND actions would seriously impede an attacker’s progress and minimize network disruption.
In addition, Darktrace Cyber AI Analyst was able to autonomously investigate registrations of the ‘PerfectData Software’ application and summarized its findings into digestible reports.
Conclusion
Due to the widespread adoption of Microsoft 365 services in the workplace and continued emphasis on a remote workforce, account hijackings now pose a more serious threat to organizations around the world than ever before. The cases discussed here illustrate the tendency of malicious actors to conduct their activities from endpoints associated with VPN services, while also registering new applications, like PerfectData Software, with malicious intent.
While it was unclear exactly why the malicious actors were using ‘PerfectData Software’ as part of their account hijacking, it is clear that either the legitimate or spoofed version of the application is becoming an very likely emergent piece of threat actor tradecraft.
Darktrace DETECT’s anomaly-based approach to threat detection allowed it to recognize that the use of ‘PerfectData Software’ represented a deviation in the SaaS user’s expected behavior. While Darktrace RESPOND, when enabled in autonomous response mode, was able to quickly take preventative action against threat actors, blocking the potential use of the application for data exfiltration or other nefarious purposes.
Appendices
MITRE ATT&CK Mapping
Reconnaissance:
• T1598 – Phishing for Information
Credential Access:
• T1110 – Brute Force
Initial Access:
• T1078.004 – Valid Accounts: Cloud Accounts
Command and Control:
• T1105 – Ingress Tool Transfer
Persistence:
• T1098.003 – Account Manipulation: Additional Cloud Roles
Collection:
• T1114 – Email Collection
Defense Evasion:
• T1564.008 – Hide Artifacts: Email Hiding Rules
Lateral Movement:
• T1534 – Internal Spearphishing
Unusual Source IPs
• 5.62.60[.]202 (AS198605 AVAST Software s.r.o.)
• 160.152.10[.]215 (AS37637 Smile-Nigeria-AS)
• 197.244.250[.]155 (AS37705 TOPNET)
• 169.159.92[.]36 (AS37122 SMILE)
• 45.62.170[.]237 (AS396073 MAJESTIC-HOSTING-01)
• 92.38.180[.]49 (AS202422 G-Core Labs S.A)
• 129.56.36[.]26 (AS327952 AS-NATCOM)
• 92.38.180[.]47 (AS202422 G-Core Labs S.A.)
• 107.179.20[.]214 (AS397086 LAYER-HOST-HOUSTON)
• 45.62.170[.]31 (AS396073 MAJESTIC-HOSTING-01)
References
[1] https://www.investing.com/academy/statistics/microsoft-facts/
[2] https://intel471.com/blog/countering-the-problem-of-credential-theft
[3] https://darktrace.com/blog/business-email-compromise-to-mass-phishing-campaign-attack-analysis
[4] https://darktrace.com/blog/breakdown-of-a-multi-account-compromise-within-office-365
Blog
Cloud
Darktrace Integrates Self-Learning AI with Amazon Security Lake to Support Security Investigations
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Darktrace has deepened its relationship with AWS by integrating its detection and response capabilities with Amazon Security Lake.
This development will allow mutual customers to seamlessly combine Darktrace AI’s bespoke understanding of their organization with the Threat Intelligence offered by other security tools, and investigate all of their alerts in one central location.
This integration will improve the value security teams get from both products, streamlining analyst workflows and improving their ability to detect and respond to the full spectrum of known and unknown cyber-threats.
How Darktrace and Amazon Security Lake augment security teams
Amazon Security Lake is a newly-released service that automatically centralizes an organization’s security data from cloud, on-premises, and custom sources into a customer owned purpose-built data lake. Both Darktrace and Amazon Security Lake support the Open Cybersecurity Schema Framework (OCSF), an open standard to simplify, combine, and analyze security logs.
Customers can store security logs, events, alerts, and other relevant data generated by various AWS services and security tools. By consolidating security data in a central lake, organizations can gain a holistic view of their security posture, perform advanced analytics, detect anomalies and open investigations to improve their security practices.
With Darktrace DETECT and RESPOND AI engines covering all assets across IT, OT, network, endpoint, IoT, email and cloud, organizations can augment the value of their security data lakes by feeding Darktrace’s rich and context-aware datapoints to Amazon Security Lake.
Amazon Security Lake empowers security teams to improve the protection of your digital estate:
- Quick and painless data normalization
- Fast-tracks ability to investigate, triage and respond to security events
- Broader visibility aids more effective decision-making
- Surfaces and prioritizes anomalies for further investigation
- Single interface for seamless data management
How will Darktrace customers benefit?
Across the Cyber AI Loop, all Darktrace solutions have been architected with AWS best practices in mind. With this integration, Darktrace is bringing together its understanding of ‘self’ for every organization with the centralized data visibility of the Amazon Security Lake. Darktrace’s unique approach to cyber security, powered by groundbreaking AI research, delivers a superior dataset based on a deep and interconnected understanding of the enterprise.
Where other cyber security solutions are trained to identify threats based on historical attack data and techniques, Darktrace DETECT gains a bespoke understanding of every digital environment, continuously analyzing users, assets, devices and the complex relationships between them. Our AI analyzes thousands of metrics to reveal subtle deviations that may signal an evolving issue – even unknown techniques and novel malware. It distinguishes between malicious and benign behavior, identifying harmful activity that typically goes unnoticed. This rich dataset is fed into RESPOND, which takes precise action to neutralize threats against any and every asset, no matter where data resides.
Both DETECT and RESPOND are supported by Darktrace Self-Learning AI, which provides full, real-time visibility into an organization’s systems and data. This always-on threat analysis already makes humans better at cyber security, improving decisions and outcomes based on total visibility of the digital ecosystem, supporting human performance with AI coverage and empowering security teams to proactively protect critical assets.
Converting Darktrace alerts to the Amazon Security Lake Open Cybersecurity Schema Framework (OCSF) supplies the Security Operations Center (SOC) and incident response team with contextualized data, empowering them to accelerate their investigation, triage and response to potential cyber threats.
Darktrace is available for purchase on the AWS Marketplace.
Learn more about how Darktrace provides full-coverage, AI-powered cloud security for AWS, or see how our customers use Darktrace in their AWS cloud environments.
