January 4, 2023

BlackMatter's Smash-and-Grab Ransom Attack Incident Analysis

Stay informed on cybersecurity trends! Read about a BlackMatters ransom attack incident and Darktrace's analysis on how RESPOND could have stopped the attack.

Written by

The Darktrace Analyst Team

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.

Written by

The Darktrace Analyst Team

Jan 2023

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:

*Figure 1- The ASCII logo which accompanied BlackMatter’s ransom note*

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.

*Figure 2- Cyber AI Analyst breaks down the stages of the attack [Note: this screenshot is from V5 of DETECT/Network]*

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

[1] https://www.designnews.com/industrial-machinery/new-age-hackers-are-ditching-smash-and-grab-techniques

[2] https://cybernews.com/cyber-war/how-do-smash-and-grab-cyberattacks-help-ukraine-in-waging-war/

[3] https://blog.google/threat-analysis-group/phishing-campaign-targets-youtube-creators-cookie-theft-malware/

[4] https://www.ukcybersecuritycouncil.org.uk/news-insights/articles/the-benefits-of-automation-to-cyber-security/

[5] https://techcrunch.com/2021/11/03/blackmatter-ransomware-shut-down/

[6] https://www.trellix.com/en-us/about/newsroom/stories/research/blackmatter-ransomware-analysis-the-dark-side-returns.html

[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

Written by

The Darktrace Analyst Team

Inside the SOC

Written by

The Darktrace Analyst Team

•

April 4, 2025

Pallavi Singh

Product Marketing Manager, OT Security & Compliance

Director of Product Management, Cado

Watch the NIS2 Webinar

Blog

Email

April 14, 2025

Email bombing exposed: Darktrace’s email defense in action

picture of a computer screen showing a password login

What is email bombing?

An email bomb attack, also known as a "spam bomb," is a cyberattack where a large volume of emails—ranging from as few as 100 to as many as several thousand—are sent to victims within a short period.

How does email bombing work?

Email bombing is a tactic that typically aims to disrupt operations and conceal malicious emails, potentially setting the stage for further social engineering attacks. Parallels can be drawn to the use of Domain Generation Algorithm (DGA) endpoints in Command-and-Control (C2) communications, where an attacker generates new and seemingly random domains in order to mask their malicious connections and evade detection.

In an email bomb attack, threat actors typically sign up their targeted recipients to a large number of email subscription services, flooding their inboxes with indirectly subscribed content [1].

Multiple threat actors have been observed utilizing this tactic, including the Ransomware-as-a-Service (RaaS) group Black Basta, also known as Storm-1811 [1] [2].

Darktrace detection of email bombing attack

In early 2025, Darktrace detected an email bomb attack where malicious actors flooded a customer's inbox while also employing social engineering techniques, specifically voice phishing (vishing). The end goal appeared to be infiltrating the customer's network by exploiting legitimate administrative tools for malicious purposes.

The emails in these attacks often bypass traditional email security tools because they are not technically classified as spam, due to the assumption that the recipient has subscribed to the service. Darktrace / EMAIL's behavioral analysis identified the mass of unusual, albeit not inherently malicious, emails that were sent to this user as part of this email bombing attack.

Email bombing attack overview

In February 2025, Darktrace observed an email bombing attack where a user received over 150 emails from 107 unique domains in under five minutes. Each of these emails bypassed a widely used and reputable Security Email Gateway (SEG) but were detected by Darktrace / EMAIL.

Figure 1: Graph showing the unusual spike in unusual emails observed by Darktrace / EMAIL.

The emails varied in senders, topics, and even languages, with several identified as being in German and Spanish. The most common theme in the subject line of these emails was account registration, indicating that the attacker used the victim’s address to sign up to various newsletters and subscriptions, prompting confirmation emails. Such confirmation emails are generally considered both important and low risk by email filters, meaning most traditional security tools would allow them without hesitation.

Additionally, many of the emails were sent using reputable marketing tools, such as Mailchimp’s Mandrill platform, which was used to send almost half of the observed emails, further adding to their legitimacy.

Figure 2: Darktrace / EMAIL’s detection of an email being sent using the Mandrill platform.

Figure 3: Darktrace / EMAIL’s detection of a large number of unusual emails sent during a short period of time.

While the individual emails detected were typically benign, such as the newsletter from a legitimate UK airport shown in Figure 3, the harmful aspect was the swarm effect caused by receiving many emails within a short period of time.

Traditional security tools, which analyze emails individually, often struggle to identify email bombing incidents. However, Darktrace / EMAIL recognized the unusual volume of new domain communication as suspicious. Had Darktrace / EMAIL been enabled in Autonomous Response mode, it would have automatically held any suspicious emails, preventing them from landing in the recipient’s inbox.

Figure 4: Example of Darktrace / EMAIL’s response to an email bombing attack taken from another customer environment.

Following the initial email bombing, the malicious actor made multiple attempts to engage the recipient in a call using Microsoft Teams, while spoofing the organizations IT department in order to establish a sense of trust and urgency – following the spike in unusual emails the user accepted the Teams call. It was later confirmed by the customer that the attacker had also targeted over 10 additional internal users with email bombing attacks and fake IT calls.

The customer also confirmed that malicious actor successfully convinced the user to divulge their credentials with them using the Microsoft Quick Assist remote management tool. While such remote management tools are typically used for legitimate administrative purposes, malicious actors can exploit them to move laterally between systems or maintain access on target networks. When these tools have been previously observed in the network, attackers may use them to pursue their goals while evading detection, commonly known as Living-off-the-Land (LOTL).

Subsequent investigation by Darktrace’s Security Operations Centre (SOC) revealed that the recipient's device began scanning and performing reconnaissance activities shortly following the Teams call, suggesting that the user inadvertently exposed their credentials, leading to the device's compromise.

Darktrace’s Cyber AI Analyst was able to identify these activities and group them together into one incident, while also highlighting the most important stages of the attack.

Figure 5: Cyber AI Analyst investigation showing the initiation of the reconnaissance/scanning activities.

The first network-level activity observed on this device was unusual LDAP reconnaissance of the wider network environment, seemingly attempting to bind to the local directory services. Following successful authentication, the device began querying the LDAP directory for information about user and root entries. Darktrace then observed the attacker performing network reconnaissance, initiating a scan of the customer’s environment and attempting to connect to other internal devices. Finally, the malicious actor proceeded to make several SMB sessions and NTLM authentication attempts to internal devices, all of which failed.

Figure 6: Device event log in Darktrace / NETWORK, showing the large volume of connections attempts over port 445.

Figure 7: Darktrace / NETWORK’s detection of the number of the login attempts via SMB/NTLM.

While Darktrace’s Autonomous Response capability suggested actions to shut down this suspicious internal connectivity, the deployment was configured in Human Confirmation Mode. This meant any actions required human approval, allowing the activities to continue until the customer’s security team intervened. If Darktrace had been set to respond autonomously, it would have blocked connections to port 445 and enforced a “pattern of life” to prevent the device from deviating from expected activities, thus shutting down the suspicious scanning.

Conclusion

Email bombing attacks can pose a serious threat to individuals and organizations by overwhelming inboxes with emails in an attempt to obfuscate potentially malicious activities, like account takeovers or credential theft. While many traditional gateways struggle to keep pace with the volume of these attacks—analyzing individual emails rather than connecting them and often failing to distinguish between legitimate and malicious activity—Darktrace is able to identify and stop these sophisticated attacks without latency.

Thanks to its Self-Learning AI and Autonomous Response capabilities, Darktrace ensures that even seemingly benign email activity is not lost in the noise.

Credit to Maria Geronikolou (Cyber Analyst and SOC Shift Supervisor) and Cameron Boyd (Cyber Security Analyst), Steven Haworth (Senior Director of Threat Modeling), Ryan Traill (Analyst Content Lead)

Appendices

[1] https://www.microsoft.com/en-us/security/blog/2024/05/15/threat-actors-misusing-quick-assist-in-social-engineering-attacks-leading-to-ransomware/

[2] https://thehackernews.com/2024/12/black-basta-ransomware-evolves-with.html

Darktrace Models Alerts

Internal Reconnaissance

· Device / Suspicious SMB Scanning Activity

· Device / Anonymous NTLM Logins

· Device / Network Scan

· Device / Network Range Scan

· Device / Suspicious Network Scan Activity

· Device / ICMP Address Scan

· Anomalous Connection / Large Volume of LDAP Download

· Device / Suspicious LDAP Search Operation

· Device / Large Number of Model Alerts

About the author

Maria Geronikolou

Cyber Analyst

Blog

Email

April 11, 2025

FedRAMP High-compliant email security protects federal agencies from nation-state attacks

U.S. government building with flag against blue sky

What is FedRAMP High Authority to Operate (ATO)?

Federal Risk and Authorization Management Program (FedRAMP®) High is a government-wide program that promotes the adoption of secure cloud services across the federal government by providing a standardized approach to security and risk assessment for cloud technologies and federal agencies, ensuring the protection of federal information.

Cybersecurity is paramount in the Defense Industrial Base (DIB), where protecting sensitive information and ensuring operational resilience from the most sophisticated adversaries has national security implications. Organizations within the DIB must comply with strict security standards to work with the U.S. federal government, and FedRAMP High is one of those standards.

Darktrace achieves FedRAMP High ATO across IT, OT, and email

Last week, Darktrace Federal shared that we achieved FedRAMP® High ATO, a significant milestone that recognizes our ability to serve federal customers across IT, OT, and email via secure cloud-native deployments.

Achieving the FedRAMP High ATO indicates that Darktrace Federal has achieved the highest standard for cloud security controls and can handle the U.S. federal government’s most sensitive, unclassified data in cloud environments.

Azure Government email security with FedRAMP High ATO

Darktrace has now released Darktrace Commercial Government Cloud High/Email (DCGC High/Email). This applies our email coverage to systems hosted in Microsoft's Azure Government, which adheres to NIST SP 800-53 controls and other federal standards. DCGC High/Email both meets and exceeds the compliance requirements of the Department of Defense’s Cybersecurity Maturity Model Certification (CMMC), providing organizations with a much-needed email security solution that delivers unparalleled, AI-driven protection against sophisticated cyber threats.

In these ways, DCGC High/Email enhances compliance, security, and operational resilience for government and federally-affiliated customers. Notably, it is crucial for securing contractors and suppliers within DIB, helping those organizations implement necessary cybersecurity practices to protect Controlled Unclassified Information (CUI) and Federal Contract Information (FCI).

Adopting DCGC High/Email ensures organizations within the DIB can work with the government without needing to invest extensive time and money into meeting the strict compliance standards.

Building DCGC High/Email to ease DIB work with the government

DCGC High/Email was built to achieve FedRAMP High standards and meet the most rigorous security standards required of our customers. This level of compliance not only allows more organizations than ever to leverage our AI-driven technology, but also ensures that customer data is protected by the highest security measures available.

The DIB has never been more critical to national security, which means they are under constant threats from nation state and cyber criminals. We built DCGC High/Email to FedRAMP High controls to ensure sensitive company and federal government communications are secured at the highest level possible.” – Marcus Fowler, CEO of Darktrace Federal

Evolving threats now necessitate DCGC High/Email

According to Darktrace’s 2025 State of AI Cybersecurity report, more than half (54%) of global government cybersecurity professionals report seeing a significant impact from AI-powered cyber threats.

These aren’t the only types of sophisticated threats. Advanced Persistent Threats (APTs) are launched by nation-states or cyber-criminal groups with the resources to coordinate and achieve long-term objectives.

These attacks are carefully tailored to specific targets, using techniques like social engineering and spear phishing to gain initial access via the inbox. Once inside, attackers move laterally through networks, often remaining undetected for months or even years, silently gathering intelligence or preparing for a decisive strike.

However, the barrier for entry for these threat actors has been lowered immensely, likely related to the observed impact of AI-powered cyber threats. Securing email environments is more important than ever.

Darktrace’s 2025 State of AI Cybersecurity report also found that 89% of government cybersecurity professionals believe AI can help significantly improve their defensive capabilities.

Darktrace's AI-powered defensive tools are uniquely capable of detecting and neutralizing APTs and other sophisticated threats, including ones that enter via the inbox. Our Self-Learning AI continuously adapts to evolving threats, providing real-time protection.

Darktrace builds to secure the DIB to the highest degree

In summary, Darktrace Federal's achievement of FedRAMP High ATO and the introduction of DCGC High/Email mark significant advancements in our ability to protect defense contractors and federal customers against sophisticated threats that other solutions miss.

For a technical review of Darktrace Federal’s Cyber AI Mission Defense™ solution, download an independent evaluation from the Technology Advancement Center here.

[related-resource]

About the author

Marcus Fowler

CEO of Darktrace Federal and SVP of Strategic Engagements and Threats

Your data. Our AI.

Elevate your network security with Darktrace AI

Get a demo

Check out this article by Darktrace: BlackMatter's Smash-and-Grab Ransom Attack Incident Analysis

BlackMatter's Smash-and-Grab Ransom Attack Incident Analysis

The Name Game: Untangling BlackMatter, REvil, and DarkSide

Attack Details

How would the attack have unfolded with RESPOND?

Why does RESPOND work?

Conclusion

List of IOCs

Reference List

Darktrace Named as Market Leader in the 2025 Omdia Market Radar for OT Cybersecurity Platforms

Fusing Vulnerability and Threat Data: Enhancing the Depth of Attack Analysis

Enjoying the blog?

More in this series

Cyberhaven Supply Chain Attack: Exploiting Browser Extensions

Darktrace's Detection of State-Linked ShadowPad Malware

Darktrace Releases Annual 2024 Threat Insights

Blog

Email

April 14, 2025

Email bombing exposed: Darktrace’s email defense in action

What is email bombing?

How does email bombing work?

Darktrace detection of email bombing attack

Email bombing attack overview

Conclusion

Appendices

Darktrace Models Alerts

Internal Reconnaissance

Blog

Email

April 11, 2025

FedRAMP High-compliant email security protects federal agencies from nation-state attacks

What is FedRAMP High Authority to Operate (ATO)?

Darktrace achieves FedRAMP High ATO across IT, OT, and email

Azure Government email security with FedRAMP High ATO

Building DCGC High/Email to ease DIB work with the government

Evolving threats now necessitate DCGC High/Email

Darktrace builds to secure the DIB to the highest degree