Modern Extortion: Detecting Data Theft From the Cloud

Sep 2022

Darktrace highlights a handful of data theft incidents on shared cloud platforms, showing that cloud computing can be a vulnerable place for modern extortion.

The ransomware industry has benefitted from a number of factors in recent years: inadequate cyber defenses, poorly regulated cryptocurrency markets, and geopolitical tensions have allowed gangs to extort increasingly large ransoms while remaining sheltered from western law enforcement [1]. However, one of the biggest success stories of the ransomware industry has been the adaptability and evolution of attacker TTPs (tactics, techniques and procedures). The WannaCry and NotPetya attacks of 2017 popularized a form of ransomware which used encryption algorithms to hold data to ransom in exchange for a decryption key. Last year in 2021, almost all ransomware strains evolved to use double extortion tactics: holding stolen data to ransom as well as encrypted data [2]. Now, some ransomware gangs have dropped encryption entirely, and are using data theft as their sole means of extortion.

Using data theft for extortion is not new. In 2020 the Finnish psychotherapy center Vastaamo had over 40,000 patient records stolen. Impacted patients were told that their psychiatric transcripts would be published online if they failed to pay a Bitcoin ransom. [3]. A later report by BlackFog in May 2021 predicted data theft extortion would become one of the key emerging cybersecurity trends that year [4]. Adoption of offline back-ups and endpoint detection had made encryption harder, while a large-scale move to Cloud and SaaS platforms offered new vectors for data theft. By moving from data encryption to data exfiltration, ransomware attackers pivoted from targeting data availability within the CIA triad (Confidentiality, Integrity, Availability) to threatening data confidentiality.

In November 2021, Darktrace detected a data theft incident following the compromise of two SaaS accounts within an American tech customer’s Office365 environment. The client was a longstanding user of Darktrace DETECT/Network, and was in the process of expanding their coverage by trialing Darktrace DETECT+RESPOND/ Apps + Cloud.

Attack Overview

On November 23^rd 2021, an Ask the Expert (ATE) ticket was raised prompting investigation into a breached SaaS model, ‘SaaS / Access / Unusual External Source for SaaS Credential Use’, and the activities of a user (censored as UserA) over the prior week.

1. Office365: UserA

The account UserA had been logging in from an unusual location in Nigeria on November 21^st. At the time of the incident there were no flags of malicious activity from this IP in widely used OSINT sources. It is also highly probable the attacker was not located in Nigeria but using Nigerian infrastructure in order to hide their true location. Regardless, the location of the login from this IP and ASN was considered highly unusual for users within the customer’s digital estate. The specific user in question most commonly accessed their account from IP ranges located in the US.

Figure 1: In the Geolocation tab of the External Sites Summary on the SaaS Console, UserA was seen logging in from Nigeria when previous logins were exclusively from USA

Further investigation revealed an additional anomaly in the Outlook Web activity of UserA. The account was using the Firefox browser to access their account for the first time in at least 4 weeks (the maximum period for which the customer stored such data). SaaS logs detailing the access of confidential folders and other suspicious actions were identified using the Advanced Search (AS) query:

@fields.saas_actor:"UserA@[REDACTED]" AND @fields.saas_software:"Firefox"

Most actions were ‘MailItemsAccessed’ events originating from IPs located in Nigeria [5,6] and one other potentially malicious IP located in the US [7].

‘MailItemsAccessed’ is part of the new Advanced Audit functionality from Microsoft and can be used to determine when email data is accessed by mail protocols and clients. A bind mail access type denotes an individual access to an email message [8].

Figure 2: AS logs shows UserA had not used Firefox to access Office365 for at least 4 weeks prior to the unusual login on the 21st November

Below are details of the main suspicious SaaS activities:

· Time: 2021-11-21 09:05:25 - 2021-11-22 16:57:39 UTC

· SaaS Actor: UserA@[REDACTED]

· SaaS Service: Office365

· SaaS Service Product: Exchange

· SaaS Software: Firefox

· SaaS Office365 Parent Folders:

          o   \Accounts/Passwords
          o   \Invoices
         o   \Sent Items
          o   \Inbox
          o   \Recoverable Items\Deletions

· SaaS Event:

          o   MailItemsAccessed
          o   UserLoggedIn
          o   Update

· SaaS Office365 Mail Access Type: Bind (47 times)

· Source IP addresses:

          o   105.112.59[.]83
          o   105.112.36[.]212
          o   154.6.17[.]16
          o   45.130.83[.]129

· SaaS User Agents:

o Client=OWA;Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:80.0) Gecko/20100101 Firefox/80.0;
o Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:80.0) Gecko/20100101 Firefox/80.0

· Total SaaS logs: 57

At the start of the month on the 5^th November, the user had also been seen logging in from a potentially malicious endpoint [9] in Europe, performing ‘MailItemsAccessed’ and ‘Updates’ events with subjects and a resource location related to invoices and wire transfers from the Sent items folder. This suggests the initial compromise had been earlier in the month, giving the threat actor time to make preparations for the final stages of the attack.

Figure 3: Event log showing the activity of UserA from IP 45.135.187[.]108

2. Office365: UserB

Looking into the model breach ‘SaaS / Access / Suspicious Credential Use And Login User-Agent’, it was seen that a second account, UserB, was also observed logging in from a rare and potentially malicious location in Bangladesh [7]. Similar to UserA, this user had previously logged in exclusively from the USA, and no other accounts within the digital estate had been observed interacting with the Bangladeshi IP address. The login event appeared to bypass MFA (Multi-factor Authentication) and a suspicious user agent, BAV2ROPC, was used. Against misconfigured accounts, this Microsoft user agent is commonly used by attackers to bypass MFA on Office365. It targets Exchange’s Basic Authentication (normally used in POP3/IMAP4 conditions) and results in an OAuth flow which circumvents the additional password security brought by MFA [10].

During the session, additional resources were accessed which appear to be associated with bill and invoice payments. In addition, on the 4^th November, two new suspicious email rules named “..” were created from rare IPs (107.10.56[.]48 and 76.189.202[.]66). This type of behavior is commonly seen during SaaS compromises to delete or forward emails. Typically, an email rule created by a human user will be named to reflect the change being made, such as ‘Move emails from Legal to Urgent’. In contrast, malicious email rules are often short and undescriptive. The rule “..” is likely to blend in without arousing suspicion, while also being easy for the attacker to create and remember.

Details of these rule changes are as follows:

·      Time: 2021-11-04 13:25:06, 2021-11-05 15:50:00 [UTC]
·      SaaS Service: Office365
·      SaaS Service Product: Exchange
·      SaaS Status Message: True
·      SaaS Source IP addresses: 107.10.56[.]48, 76.189.202[.]66
·      SaaS Account Name: O365
·      SaaS Actor: UserB@[REDACTED]
·      SaaS Event: SetInboxRule
·      SaaS Office365 Modified Property Names:
          o   AlwaysDeleteOutlookRulesBlob, Force, Identity, MoveToFolder, Name, FromAddressContainsWords, StopProcessingRules
          o   AlwaysDeleteOutlookRulesBlob, Force, Identity, Name, FromAddressContainsWords, StopProcessingRules
·      SaaS Resource Name: ..

During cloud account compromises, attackers will often use sync operations to download emails to their local email client. During the operations, these clients typically download a large set of mail items from the cloud to a local computer. If the attacker is able to sync all mail items to their mail client, the entire mailbox can be compromised. The attacker is able to disconnect from the account and review and search the email without generating additional event logs.

Both accounts UserA and UserB were observed using ‘MailItemsAccessed’ sync operations between the 1^st and 23^rd November when this attack occurred. However, based on the originating IP of the sync operations, the activity is likely to have been initiated by the legitimate, US-based users. Once the security team were able to confirm the events were expected and legitimate, they could establish that the contents of the mailbox were not a part of the data breach.

Accomplish Mission

After gaining access to the Office365 accounts, sensitive data was downloaded by the attackers to their local system. Either on or before 14^th December, the attacker had seemingly uploaded the documents onto a data leak website. In total, 130MB of data had been made available for download in two separate packages. The packages included audit and accounting financial documents, with file extensions such as DB, XLSX, and PDF.

Figure 4: The two data packages uploaded by the attacker and the extracted contents

In a sample of past SaaS activity of UserA, the subject and attachments appear related to the ‘OUTSTANDING PREPAY WIRES 2021’ excel document found from the data leak website in Figure 4, suggesting a further possibility that the account was associated with the leaked data.

Historic SaaS activity associated with UserA:

·      Time: 2021-11-05 21:21:18 [UTC]
·      SaaS Office365 Logon Type: Owner
·      Protocol: OFFICE365
·      SaaS Account Name: O365
·      SaaS Actor: UserA@[REDACTED].com
·      SaaS Event: Send
·      SaaS Service: Office365
·      SaaS Service Product: Exchange
·      SaaS Status Message: Succeeded
·      SaaS Office365 Attachment: WIRE 2021.xlsx (92406b); image.png (9084b); image.png (1454b); image.png (1648b); image.png (1691b); image.png (1909b); image.png (2094b)
·      SaaS Office365 Subject: Wires 11/8/21
·      SaaS Resource Location: \Drafts
·      SaaS User Agent: Client=OWA;Action=ViaProxy

Based on the available evidence, it is highly likely that the data packages contain the data stolen during the account compromise the previous month.

Once the credentials of an Office365 account are stolen, an attacker can not only access the user's mailbox, but also a full range of Office365 applications such as SharePoint folders, Teams Chat, or files in the user's OneDrive [11]. For example, files shared in Teams chat are stored in OneDrive for Business in a folder named Microsoft Teams Chat Files in the default Document library on SharePoint. One of the files visible on the data leak website, called ‘[REDACTED] CONTRACT.3.1.2020.pdf’, was also observed in the default document folder of a third user account (UserC) within the victim organization, suggesting the compromised accounts may have been able to access shared files stored on other accounts by moving laterally via other O365 applications such as Teams.

One example can be seen in the below AS logs:

·      Time: 2021-11-11 01:58:35 [UTC]
·      SaaS Resource Type: File
·      Protocol: OFFICE365
·      SaaS Account Name: 0365
·      SaaS Actor: UserC@[REDACTED]
·      SaaS Event: FilePreviewed
·      SaaS Service Product: OneDrive
·      SaaS Metric: ResourceViewed
·      SaaS Office365 Application Name: Media Analysis and Transformation Service
·      SaaS Office365 File Extension: pdf
·      SaaS Resource Location: https://[REDACTED]-my.sharepoint.com/personal/userC_[REDACTED]_com/Documents/Microsoft Teams Chat Files/[REDACTED] CONTRACT 3.1.2020.pdf
·      SaaS Resource Name: [REDACTED] CONTRACT 3.1.2020.pdf
·      SaaS Service: Office365
·      SaaS Service Product: OneDrive
·      SaaS User Agent: OneDriveMpc-Transform_Thumbnail/1.0

In the period between the 1^st and 30^th November, the customer’s Darktrace DETECT/Apps trial had raised multiple high-level alerts associated with SaaS account compromise, but there was no evidence of file encryption.

Establish Foothold

Looking back at the start of the attack, it is unclear exactly how the attacker evaded the customer’s pre-existing security stack. At the time of the incident, the victim was using a Barracuda email gateway and Microsoft 365 Threat Management for their cloud environment.

Darktrace detected no indication the accounts were compromised via credential bruteforcing, which would have enabled the attacker to bypass the Azure Active Directory smart lockout (if enabled). The credentials may have been harvested via a phishing campaign which successfully evaded the list of known ‘bad’ domains maintained by their email gateway.

Upon gaining access to the account, the Microsoft Defender for Cloud Apps anomaly detection policies would have been expected to raise an alert [12]. In this instance, the unusual login from Nigeria occurred over 16 hours after the previous login from the US, potentially evading anomaly detection policies such as the ‘Impossible Travel’ rule.

Figure 5: Event log showing the user accessing mail from USA a day before the suspicious usage from Nigeria

Darktrace Coverage

Darktrace DETECT

Throughout this event, high scoring model breaches associated with the attack were visible in the customer’s SaaS Console. In addition, there were two Cyber AI Analyst incidents for ‘Possible Account Hijack’ associated with the two compromised SaaS Office365 accounts, UserA and UserB. The visibility given by Darktrace DETECT also enabled the security team to confirm which files had been accessed and were likely part of the data leak.

Figure 6: Example Cyber AI Analyst incident of UserB SaaS Office365 account

Darktrace RESPOND

In this incident, the attackers successfully compromised O365 accounts in order to exfiltrate customer data. Whilst Darktrace RESPOND/Apps was being trialed and suggested several actions, it was configured in human confirmation mode. The following RESPOND/Apps actions were advised for these activities:

· ‘Antigena [RESPOND] Unusual Access Block’ triggered by the successful login from an unusual IP address, would have actioned the ‘Block IP’ inhibitor, preventing access to the account from the unusual IP for up to 24 hours
· ‘Suspicious Source Activity Block’, triggered by the suspicious user agent used to bypass MFA, would have actioned the ‘Disable User’ inhibitor, disabling the user account for up to 24 hours

During this incident, Darktrace RESPOND/Network was being used in fully autonomous mode in order to prevent the threat actor from pivoting into the network. The security team were unable to conclusively say if any attempts by the attacker to do this had been made.

Concluding Thoughts

Data theft extortion has become a widely used attack technique, and ransomware gangs may increasingly use this technique alone to target organizations without secure data encryption and storage policies.

This case study describes a SaaS data theft extortion incident which bypassed MFA and existing security tools. The attacker appeared to compromise credentials without bruteforce activity, possibly with the use of social engineering through phishing. However, from the first new login, Darktrace DETECT identified the unusual credential use in spite of it being an existing account. Had Darktrace RESPOND/Apps been configured, it would have autonomously responded to halt this login and prevent the attacker from accomplishing their data theft mission.

Thanks to Oakley Cox, Brianna Leddy and Shuh Chin Goh for their contributions.

Appendices

References

[1] https://securelist.com/new-ransomware-trends-in-2022/106457/

[2] https://www.itpro.co.uk/security/ransomware/367624/the-rise-of-double-extortion-ransomware

[3] https://www.malwarebytes.com/blog/news/2020/10/vastaamo-psychotherapy-data-breach-sees-the-most-vulnerable-victims-extorted

[4] https://www.blackfog.com/shift-from-ransomware-to-data-theft-extortion/

[5] https://www.abuseipdb.com/check/105.112.59.83

[6] https://www.abuseipdb.com/check/105.112.36.212

[7] https://www.abuseipdb.com/check/45.130.83.129

[8] https://docs.microsoft.com/en-us/microsoft-365/compliance/mailitemsaccessed-forensics-investigations?view=o365-worldwide

[9] https://www.abuseipdb.com/check/45.135.187.108

[10] https://www.virustotal.com/gui/ip-address/45.137.20.65/details

[11] https://tidorg.com/new-bec-phishing-attack-steals-office-365-credentials-and-bypasses-mfa/

[12] https://docs.microsoft.com/en-us/microsoft-365/security/office-365-security/responding-to-a-compromised-email-account?view=o365-worldwide

INSIDE THE SOC

Darktrace cyber analysts are world-class experts in threat intelligence, threat hunting and incident response, and provide 24/7 SOC support to thousands of Darktrace customers around the globe. Inside the SOC is exclusively authored by these experts, providing analysis of cyber incidents and threat trends, based on real-world experience in the field.

AUTHOR

ABOUT ThE AUTHOR

Adrianne Marques

Senior Research Analyst

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Thought Leadership

The State of AI in Cybersecurity: Understanding AI Technologies

Jul 2024

About the State of AI Cybersecurity Report

Darktrace surveyed 1,800 CISOs, security leaders, administrators, and practitioners from industries around the globe. Our research was conducted to understand how the adoption of new AI-powered offensive and defensive cybersecurity technologies are being managed by organizations.

This blog continues the conversation from “The State of AI in Cybersecurity: Unveiling Global Insights from 1,800 Security Practitioners”. This blog will focus on security professionals’ understanding of AI technologies in cybersecurity tools.

To access download the full report, click here.

How familiar are security professionals with supervised machine learning

Just 31% of security professionals report that they are “very familiar” with supervised machine learning.

Many participants admitted unfamiliarity with various AI types. Less than one-third felt "very familiar" with the technologies surveyed: only 31% with supervised machine learning and 28% with natural language processing (NLP).

Most participants were "somewhat" familiar, ranging from 46% for supervised machine learning to 36% for generative adversarial networks (GANs). Executives and those in larger organizations reported the highest familiarity.

Combining "very" and "somewhat" familiar responses, 77% had familiarity with supervised machine learning, 74% generative AI, and 73% NLP. With generative AI getting so much media attention, and NLP being the broader area of AI that encompasses generative AI, these results may indicate that stakeholders are understanding the topic on the basis of buzz, not hands-on work with the technologies.

If defenders hope to get ahead of attackers, they will need to go beyond supervised learning algorithms trained on known attack patterns and generative AI. Instead, they’ll need to adopt a comprehensive toolkit comprised of multiple, varied AI approaches—including unsupervised algorithms that continuously learn from an organization’s specific data rather than relying on big data generalizations.

Different types of AI

Different types of AI have different strengths and use cases in cyber security. It’s important to choose the right technique for what you’re trying to achieve.

Supervised machine learning: Applied more often than any other type of AI in cyber security. Trained on human attack patterns and historical threat intelligence.

Large language models (LLMs): Applies deep learning models trained on extremely large data sets to understand, summarize, and generate new content. Used in generative AI tools.

Natural language processing (NLP): Applies computational techniques to process and understand human language.

Unsupervised machine learning: Continuously learns from raw, unstructured data to identify deviations that represent true anomalies.

What impact will generative AI have on the cybersecurity field?

More than half of security professionals (57%) believe that generative AI will have a bigger impact on their field over the next few years than other types of AI.

Chart showing the types of AI expected to impact security the most — Figure 1: Chart from Darktrace's State of AI in Cybersecurity Report

Security stakeholders are highly aware of generative AI and LLMs, viewing them as pivotal to the field's future. Generative AI excels at abstracting information, automating tasks, and facilitating human-computer interaction. However, LLMs can "hallucinate" due to training data errors and are vulnerable to prompt injection attacks. Despite improvements in securing LLMs, the best cyber defenses use a mix of AI types for enhanced accuracy and capability.

AI education is crucial as industry expectations for generative AI grow. Leaders and practitioners need to understand where and how to use AI while managing risks. As they learn more, there will be a shift from generative AI to broader AI applications.

Do security professionals fully understand the different types of AI in security products?

Only 26% of security professionals report a full understanding of the different types of AI in use within security products.

Confusion is prevalent in today’s marketplace. Our survey found that only 26% of respondents fully understand the AI types in their security stack, while 31% are unsure or confused by vendor claims. Nearly 65% believe generative AI is mainly used in cybersecurity, though it’s only useful for identifying phishing emails. This highlights a gap between user expectations and vendor delivery, with too much focus on generative AI.

Key findings include:

Executives and managers report higher understanding than practitioners.

Larger organizations have better understanding due to greater specialization.

As AI evolves, vendors are rapidly introducing new solutions faster than practitioners can learn to use them. There's a strong need for greater vendor transparency and more education for users to maximize the technology's value.

To help ease confusion around AI technologies in cybersecurity, Darktrace has released the CISO’s Guide to Cyber AI. A comprehensive white paper that categorizes the different applications of AI in cybersecurity. Download the White Paper here.

Do security professionals believe generative AI alone is enough to stop zero-day threats?

No! 86% of survey participants believe generative AI alone is NOT enough to stop zero-day threats

This consensus spans all geographies, organization sizes, and roles, though executives are slightly less likely to agree. Asia-Pacific participants agree more, while U.S. participants agree less.

Despite expecting generative AI to have the most impact, respondents recognize its limited security use cases and its need to work alongside other AI types. This highlights the necessity for vendor transparency and varied AI approaches for effective security across threat prevention, detection, and response.

Stakeholders must understand how AI solutions work to ensure they offer advanced, rather than outdated, threat detection methods. The survey shows awareness that old methods are insufficient.

To access the full report, click here.

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Inside the SOC

Jupyter Ascending: Darktrace’s Investigation of the Adaptive Jupyter Information Stealer

Jul 2024

What is Malware as a Service (MaaS)?

Malware as a Service (MaaS) is a model where cybercriminals develop and sell or lease malware to other attackers.

This approach allows individuals or groups with limited technical skills to launch sophisticated cyberattacks by purchasing or renting malware tools and services. MaaS is often provided through online marketplaces on the dark web, where sellers offer various types of malware, including ransomware, spyware, and trojans, along with support services such as updates and customer support.

The Growing MaaS Marketplace

The Malware-as-a-Service (MaaS) marketplace is rapidly expanding, with new strains of malware being regularly introduced and attracting waves of new and previous attackers. The low barrier for entry, combined with the subscription-like accessibility and lucrative business model, has made MaaS a prevalent tool for cybercriminals. As a result, MaaS has become a significant concern for organizations and their security teams, necessitating heightened vigilance and advanced defense strategies.

Examples of Malware as a Service

‍Ransomware as a Service (RaaS): Providers offer ransomware kits that allow users to launch ransomware attacks and share the ransom payments with the service provider.‍
Phishing as a Service: Services that provide phishing kits, including templates and email lists, to facilitate phishing campaigns.‍
Botnet as a Service: Renting out botnets to perform distributed denial-of-service (DDoS) attacks or other malicious activities.
Information Stealer: Information stealers are a type of malware specifically designed to collect sensitive data from infected systems, such as login credentials, credit card numbers, personal identification information, and other valuable data.

How does information stealer malware work?

Information stealers are an often-discussed type MaaS tool used to harvest personal and proprietary information such as administrative credentials, banking information, and cryptocurrency wallet details. This information is then exfiltrated from target networks via command-and-control (C2) communication, allowing threat actors to monetize the data. Information stealers have also increasingly been used as an initial access vector for high impact breaches including ransomware attacks, employing both double and triple extortion tactics.

After investigating several prominent information stealers in recent years, the Darktrace Threat Research team launched an investigation into indicators of compromise (IoCs) associated with another variant in late 2023, namely the Jupyter information stealer.

What is Jupyter information stealer and how does it work?

The Jupyter information stealer (also known as Yellow Cockatoo, SolarMarker, and Polazert) was first observed in the wild in late 2020. Multiple variants have since become part of the wider threat landscape, however, towards the end of 2023 a new variant was observed. This latest variant achieved greater stealth and updated its delivery method, targeting browser extensions such as Edge, Firefox, and Chrome via search engine optimization (SEO) poisoning and malvertising. This then redirects users to download malicious files that typically impersonate legitimate software, and finally initiates the infection and the attack chain for Jupyter [3][4]. In recently noted cases, users download malicious executables for Jupyter via installer packages created using InnoSetup – an open-source compiler used to create installation packages in the Windows OS.

The latest release of Jupyter reportedly takes advantage of signed digital certificates to add credibility to downloaded executables, further supplementing its already existing tactics, techniques and procedures (TTPs) for detection evasion and sophistication [4]. Jupyter does this while still maintaining features observed in other iterations, such as dropping files into the %TEMP% folder of a system and using PowerShell to decrypt and load content into memory [4]. Another reported feature includes backdoor functionality such as:

C2 infrastructure
Ability to download and execute malware
Execution of PowerShell scripts and commands
Injecting shellcode into legitimate windows applications

Darktrace Coverage of Jupyter information stealer

In September 2023, Darktrace’s Threat Research team first investigated Jupyter and discovered multiple IoCs and TTPs associated with the info-stealer across the customer base. Across most investigated networks during this time, Darktrace observed the following activity:

HTTP POST requests over destination port 80 to rare external IP addresses (some of these connections were also made via port 8089 and 8090 with no prior hostname lookup).
HTTP POST requests specifically to the root directory of a rare external endpoint.
Data streams being sent to unusual external endpoints
Anomalous PowerShell execution was observed on numerous affected networks.

Taking a further look at the activity patterns detected, Darktrace identified a series of HTTP POST requests within one customer’s environment on December 7, 2023. The HTTP POST requests were made to the root directory of an external IP address, namely 146.70.71[.]135, which had never previously been observed on the network. This IP address was later reported to be malicious and associated with Jupyter (SolarMarker) by open-source intelligence (OSINT) [5].

Figure 1: Device Event Log indicating several connections from the source device to the rare external IP address 146.70.71[.]135 over port 80.

This activity triggered the Darktrace / NETWORK model, ‘Anomalous Connection / Posting HTTP to IP Without Hostname’. This model alerts for devices that have been seen posting data out of the network to rare external endpoints without a hostname. Further investigation into the offending device revealed a significant increase in external data transfers around the time Darktrace alerted the activity.

Figure 2: This External Data Transfer graph demonstrates a spike in external data transfer from the internal device indicated at the top of the graph on December 7, 2023, with a time lapse shown of one week prior.

Packet capture (PCAP) analysis of this activity also demonstrates possible external data transfer, with the device observed making a POST request to the root directory of the malicious endpoint, 146.70.71[.]135.

Figure 3: PCAP of a HTTP POST request showing streams of data being sent to the endpoint, 146.70.71[.]135.

In other cases investigated by the Darktrace Threat Research team, connections to the rare external endpoint 67.43.235[.]218 were detected on port 8089 and 8090. This endpoint was also linked to Jupyter information stealer by OSINT sources [6].

Darktrace recognized that such suspicious connections represented unusual activity and raised several model alerts on multiple customer environments, including ‘Compromise / Large Number of Suspicious Successful Connections’ and ‘Anomalous Connection / Multiple Connections to New External TCP Port’.

In one instance, a device that was observed performing many suspicious connections to 67.43.235[.]218 was later observed making suspicious HTTP POST connections to other malicious IP addresses. This included 2.58.14[.]246, 91.206.178[.]109, and 78.135.73[.]176, all of which had been linked to Jupyter information stealer by OSINT sources [7] [8] [9].

Darktrace further observed activity likely indicative of data streams being exfiltrated to Jupyter information stealer C2 endpoints.

Figure 4: Graph displaying the significant increase in the number of HTTP POST requests with No Get made by an affected device, likely indicative of Jupyter information stealer C2 activity.

In several cases, Darktrace was able to leverage customer integrations with other security vendors to add additional context to its own model alerts. For example, numerous customers who had integrated Darktrace with Microsoft Defender received security integration alerts that enriched Darktrace’s model alerts with additional intelligence, linking suspicious activity to Jupyter information stealer actors.

Figure 5: The security integration model alerts ‘Security Integration / Low Severity Integration Detection’ and (right image) ‘Security Integration / High Severity Integration Detection’, linking suspicious activity observed by Darktrace with Jupyter information stealer (SolarMarker).

Conclusion

The MaaS ecosystems continue to dominate the current threat landscape and the increasing sophistication of MaaS variants, featuring advanced defense evasion techniques, poses significant risks once deployed on target networks.

Leveraging anomaly-based detections is crucial for staying ahead of evolving MaaS threats like Jupyter information stealer. By adopting AI-driven security tools like Darktrace / NETWORK, organizations can more quickly identify and effectively detect and respond to potential threats as soon as they emerge. This is especially crucial given the rise of stealthy information stealing malware strains like Jupyter which cannot only harvest and steal sensitive data, but also serve as a gateway to potentially disruptive ransomware attacks.

Credit to Nahisha Nobregas (Senior Cyber Analyst), Vivek Rajan (Cyber Analyst)

References

1. https://www.paloaltonetworks.com/cyberpedia/what-is-multi-extortion-ransomware

2. https://flashpoint.io/blog/evolution-stealer-malware/

3. https://blogs.vmware.com/security/2023/11/jupyter-rising-an-update-on-jupyter-infostealer.html

4. https://www.morphisec.com/hubfs/eBooks_and_Whitepapers/Jupyter%20Infostealer%20WEB.pdf

5. https://www.virustotal.com/gui/ip-address/146.70.71.135

6. https://www.virustotal.com/gui/ip-address/67.43.235.218/community

7. https://www.virustotal.com/gui/ip-address/2.58.14.246/community

8. https://www.virustotal.com/gui/ip-address/91.206.178.109/community

9. https://www.virustotal.com/gui/ip-address/78.135.73.176/community

Appendices

Darktrace Model Detections

Anomalous Connection / Posting HTTP to IP Without Hostname
Compromise / HTTP Beaconing to Rare Destination
Unusual Activity / Unusual External Data to New Endpoints
Compromise / Slow Beaconing Activity To External Rare
Compromise / Large Number of Suspicious Successful Connections
Anomalous Connection / Multiple Failed Connections to Rare Endpoint
Compromise / Excessive Posts to Root
Compromise / Sustained SSL or HTTP Increase
Security Integration / High Severity Integration Detection
Security Integration / Low Severity Integration Detection
Anomalous Connection / Multiple Connections to New External TCP Port
Unusual Activity / Unusual External Data Transfer

AI Analyst Incidents:

Unusual Repeated Connections
Possible HTTP Command and Control to Multiple Endpoints
Possible HTTP Command and Control

List of IoCs

Indicators – Type – Description

‍

146.70.71[.]135

IP Address