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Inside the SOC
BlackMatter's Smash-and-Grab tactics and the need for RESPOND
Only a few years ago, popular reporting announced that the days of smash-and-grab attacks were over and that a new breed of hackers were taking over with subtler, ‘low-and-slow’ tactics [1]. Although these have undoubtedly appeared, smash-and-grab have quickly become overlooked – perhaps with worrying consequences. Last year, Google saw repeated phishing campaigns using cookie theft malware and most recently, reports of hacktivists using similar techniques have been identified during the 2022 Ukraine Conflict [2 & 3]. Where did their inspiration come from? For larger APT groups such as BlackMatter, which first appeared in the summer of 2021, smash-and-grabs never went out of fashion.
This blog dissects a BlackMatter ransomware attack that hit an organization trialing Darktrace back in 2021. The case reveals what can happen when a security team does not react to high-priority alerts.
When entire ransomware attacks can be carried out over the course of just 48 hours, there is a high risk to relying on security teams to react to detection notifications and prevent damage before the threat escalates. Although there has been hesitancy in its uptake [4], this blog also demonstrates the need for automated response solutions like Darktrace RESPOND.
The Name Game: Untangling BlackMatter, REvil, and DarkSide
Despite being a short-lived criminal organization on the surface [5], a number of parallels have now been drawn between the TTPs (Tactics, Techniques and Procedures) of the newer BlackMatter group and those of the retired REvil and DarkSide organizations [6].
Prior to their retirement, DarkSide and REvil were perhaps the biggest names in cyber-crime, responsible for two of last year’s most devastating ransomware attacks. Less than two weeks after the Colonial Pipeline attack, DarkSide announced it was shutting down its operation [7]. Meanwhile the FBI shutdown REvil in January 2022 after its devastating Fourth of July Kaseya attacks and a failed return in September [8]. It is now suspected that members from one or both went on to form BlackMatter.
This rebranding strategy parallels the smash-and-grab attacks these groups now increasingly employ: they make their money, and a lot of noise, and when they’re found out, they disappear before organizations or governments can pull together their threat intelligence and organize an effective response. When they return days, weeks or months later, they do so having implemented enough small changes to render themselves and their attacks unrecognizable. That is how DarkSide can become BlackMatter, and how its attacks can slip through security systems trained on previously encountered threats.
Attack Details
In September 2021 Darktrace was monitoring a US marketing agency which became the victim of a double extortion ransomware attack that bore hallmarks of a BlackMatter operation. This began when a single domain-authenticated device joined the company’s network. This was likely a pre-infected company device being reconnected after some time offline.
Only 15 minutes after joining, the device began SMB and ICMP scanning activities towards over 1000 different internal IPs. There was also a large spike of requests for Epmapper, which suggested an intent for RPC-based lateral movement. Although one credential was particularly prominent, multiple were used including labelled admin credentials. Given it’s unexpected nature, this recon quickly triggered a chain of DETECT/Network model breaches which ensured that Darktrace’s SOC were alerted via the Proactive Threat Notification service. Whilst SOC analysts began to triage the activity, the organization failed to act on any of the alerts they received, leaving the detected threat to take root within their digital environment.
Shortly after, a series of C2 beaconing occurred towards an endpoint associated with Cobalt Strike [9]. This was accompanied by a range of anomalous WMI bind requests to svcctl, SecAddr and further RPC connections. These allowed the initial compromised device to quickly infect 11 other devices. With continued scanning over the next day, valuable data was soon identified. Across several transfers, 230GB of internal data was then exfiltrated from four file servers via SSH port 22. This data was then made unusable to the organization through encryption occurring via SMB Writes and Moves/Renames with the randomly generated extension ‘.qHefKSmfd’. Finally a ransom note titled ‘qHefKSmfd.README.txt’ was dropped.
This ransom note was appended with the BlackMatter ASCII logo:
Although Darktrace DETECT and Cyber AI Analyst continued to provide live alerting, the actor successfully accomplished their mission.
There are numerous reasons that an organization may fail to organize a response to a threat, (including resource shortages, out of hours attacks, and groups that simply move too fast). Without Darktrace’s RESPOND capabilities enabled, the threat actors could proceed this attack without obstacles.
How would the attack have unfolded with RESPOND?
Armed with Darktrace’s evolving knowledge of ‘self’ for the customer’s unique digital environment, RESPOND would have activated within seconds of the first network scan, which was recognized as highly anomalous. The standard action taken here would usually involve enforcing the standard ‘pattern of life’ for the compromised device over a set time period in order to halt the anomaly while allowing the business to continue operating as normal.
RESPOND constantly re-evaluates threats as attacks unfold. Had the first stage still been successful, it would have continued to take targeted action at each corresponding stage of this attack. RESPOND models would have alerted to block the external connections to C2 servers over port 443, the outbound exfil attempts and crucially the SMB write activity over port 445 related to encryption.
As DETECT and RESPOND feed into one another, Darktrace would have continued to assess its actions as BlackMatter pivoted tactics. These actions buy back critical time for security teams that may not be in operation over the weekend, and stun the attacker into place without applying overly aggressive responses that create more problems than they solve.
Ultimately although this incident did not resolve autonomously, in response to the ransom event, Darktrace offered to enable RESPOND and set it in active mode for ransomware indicators across all client and server devices. This ensured an event like this would not occur again.
Why does RESPOND work?
Response solutions must be accurate enough to fire only when there is a genuine threat, configurable enough to let the user stay in the driver’s seat, and intelligent enough to know the right action to take to contain only the malicious activity- without disrupting normal business operations.
This is only possible if you can establish what ‘normal’ is for any one organization. And this is how Darktrace’s RESPOND product family ensures its actions are targeted and proportionate. By feeding off DETECT alerting which highlights subtle or large deviations across the network, cloud and SaaS, RESPOND can provide a measured response to the potential threat. This includes actions such as:
- Enforcing the device’s ‘pattern of life’ for a given length of time
- Enforcing the ‘group pattern of life’ (stopping a device from doing anything its peers haven’t done in the past)
- Blocking connections of a certain type to a certain destination
- Logging out of a cloud account
- ‘Smart quarantining’ an endpoint device- maintaining access to VPNs and company’s AV solution
Conclusion
In its report on BlackMatter [10], CISA recommended that organizations invest in network monitoring tools with the capacity to investigate anomalous activity. Picking up on unusual behavior rather than predetermined rules and signatures is an important step in fighting back against new threats. As this particular story shows, however, detection alone is not always enough. Turning on RESPOND, which takes immediate and precise action to contain threats, regardless of when and where they come in, is the best way to counter smash-and-grab attacks and protect organizations’ digital assets. There is little doubt that the threat actors behind BlackMatter will or have already returned with new names and strategies- but organizations with RESPOND will be ready for them.
Appendices
Darktrace Model Detections (in order of breach)
Those with the ‘PTN’ prefix were alerted directly to Darktrace’s 24/7 SOC team.
- Device / ICMP Address Scan
- Device / Suspicious SMB Scanning Activity
- (PTN) Device / Suspicious Network Scan Activity
- Anomalous Connection / SMB Enumeration
- Device / Possible RPC Lateral Movement
- Device / Active Directory Reconnaissance
- Unusual Activity / Possible RPC Recon Activity
- Device / Possible SMB/NTLM Reconnaissance
- Compliance / Default Credential Usage
- Device / New or Unusual Remote Command Execution
- Anomalous Connection / New or Uncommon Service Control
- Device / New or Uncommon SMB Named Pipe
- Device / SMB Session Bruteforce
- Device / New or Uncommon WMI Activity
- (PTN) Device / Multiple Lateral Movement Model Breaches
- Compromise / Sustained SSL or HTTP Increase
- Compromise / SSL or HTTP Beacon
- Compromise / Sustained TCP Beaconing Activity To Rare Endpoint
- Device / Anomalous SMB Followed By Multiple Model Breaches
- Device / Anomalous RDP Followed By Multiple Model Breaches
- Anomalous Server Activity / Rare External from Server
- Anomalous Connection / Anomalous SSL without SNI to New External
- Anomalous Connection / Rare External SSL Self-Signed
- Device / Long Agent Connection to New Endpoint
- Compliance / SMB Drive Write
- Anomalous Connection / Unusual Admin SMB Session
- Anomalous Connection / High Volume of New or Uncommon Service Control
- Anomalous Connection / Unusual Admin RDP Session
- Device / Suspicious File Writes to Multiple Hidden SMB Shares
- Anomalous Connection / Multiple Connections to New External TCP Port
- Compliance / SSH to Rare External Destination
- Anomalous Connection / Uncommon 1 GiB Outbound
- Anomalous Connection / Data Sent to Rare Domain
- Anomalous Connection / Download and Upload
- (PTN) Unusual Activity / Enhanced Unusual External Data Transfer
- Anomalous File / Internal / Additional Extension Appended to SMB File
- (PTN) Compromise / Ransomware / Suspicious SMB Activity
List of IOCs
Reference List
[2] https://cybernews.com/cyber-war/how-do-smash-and-grab-cyberattacks-help-ukraine-in-waging-war/
[5] https://techcrunch.com/2021/11/03/blackmatter-ransomware-shut-down/
[7] https://www.nytimes.com/2021/05/14/business/darkside-pipeline-hack.html
[8] https://techcrunch.com/2022/01/14/fsb-revil-ransomware/
[9] https://www.virustotal.com/gui/domain/georgiaonsale.com/community
[10] https://www.cisa.gov/uscert/ncas/alerts/aa21-291a
Credit to: Andras Balogh, SOC Analyst and Gabriel Few-Wiegratz, Threat Intelligence Content Production Lead
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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
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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.
