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December 21, 2020

How AI Stopped a WastedLocker Ransomware Intrusion & Fast

Stop WastedLocker ransomware in its tracks with Darktrace AI technology. Learn about how AI detected a recent attack using 'Living off the Land' techniques.
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
Max Heinemeyer
Global Field CISO
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21
Dec 2020

Since first being discovered in May 2020, WastedLocker has made quite a name for itself, quickly becoming an issue for businesses and cyber security firms around the world. WastedLocker is known for its sophisticated methods of obfuscation and steep ransom demands.

Its use of ‘Living off the Land’ techniques makes a WastedLocker attack extremely difficult for legacy security tools to detect. An ever-decreasing dwell time – the time between initial intrusion and final execution – means human responders alone struggle to contain the ransomware variant before damage is done.

This blog examines the anatomy of a WastedLocker intrusion that targeted a US agricultural organization in December. Darktrace’s AI detected and investigated the incident in real time, and we can see how Darktrace RESPOND would have autonomously taken action to stop the attack before encryption had begun.

As ransomware dwell time shrinks to hours rather than days, security teams are increasingly relying on artificial intelligence to stop threats from escalating at the earliest signs of compromise – containing attacks even when they strike at night or on the weekend.

How the WastedLocker attack unfolded

Figure 1: A timeline of the attack

Initial intrusion

The initial infection appears to have taken place when an employee was deceived into downloading a fake browser update. Darktrace AI was monitoring the behavior of around 5,000 devices at the organization, continuously adapting its understanding of the evolving ‘pattern of life’. It detected the first signs of a threat when a virtual desktop device started making HTTP and HTTPS connections to external destinations that were deemed unusual for the organization. The graph below depicts how the patient zero device exhibited a spike in internal connections around December 4.

Figure 2: The patient zero device exhibiting a spike in internal connections, with orange dots indicating model breaches of varying severity

Reconnaissance

Attempted reconnaissance began just 11 minutes after the initial intrusion. Again, Darktrace immediately picked up on the activity, detecting unusual ICMP ping scans and targeted address scans on ports 135, 139 and 445; presumably as the attacker looked for potential further Windows targets. The below demonstrates the scanning detections based on the unusual number of new failed connections.

Figure 3: Darktrace detecting an unusual number of failed connections

Lateral movement

The attacker used an existing administrative credential to authenticate against a Domain Controller, initiating new service control over SMB. Darktrace picked this up immediately, identifying it as unusual behavior.

Figure 4: Darktrace identifying the DCE-RPC requests
Figure 5: Darktrace surfacing the SMB writes

Several hours later – and in the early hours of the morning – the attacker used a temporary admin account ‘tempadmin’ to move to another Domain Controller over SMB. Darktrace instantly detected this as it was highly unusual to use a temporary admin account to connect from a virtual desktop to a Domain Controller.

Figure 6: Further anomalous connections detected the following day

Lock and load: WastedLocker prepares to strike

During the beaconing activity, the attacker also conducted internal reconnaissance and managed to establish successful administrative and remote connections to other internal devices by using tools already present. Soon after, a transfer of suspicious .csproj files was detected by Darktrace, and at least four other devices began exhibiting similar command and control (C2) communications.

However, with Darktrace’s real-time detections – and Cyber AI Analyst investigating and reporting on the incident in a number of minutes, the security team were able to contain the attack, taking the infected devices offline.

Automated investigations with Cyber AI Analyst

Darktrace’s Cyber AI Analyst launched an automatic investigation around every anomaly detection, forming hypotheses, asking questions about its own findings, and forming accurate answers at machine speed. It then generated high-level, intuitive incident summaries for the security team. Over the 48 hour period, the AI Analyst surfaced just six security incidents in total, with three of these directly relating to the WastedLocker intrusion.

Figure 7: The Cyber AI Analyst threat tray

The snapshot below shows a VMWare device (patient zero) making repeated external connections to rare destinations, scanning the network and using new admin credentials.

Figure 8: Cyber AI Analyst investigates

Darktrace RESPOND: AI that responds when the security team cannot

Darktrace RESPOND – the world’s first and only Autonomous Response technology – was configured in passive mode, meaning it did not actively interfere with the attack, but if we dive back into the Threat Visualizer we can see that Antigena in fully autonomous mode would have responded to the attack at this early stage, buying the security team valuable time.

In this case, after the initial unusual SSL C2 detection (based on a combination of destination rarity, JA3 unusualness and frequency analysis), RESPOND (formerly known as 'Antigena', as shown in the screenshots below) suggested instantly blocking the C2 traffic on port 443 and parallel internal scanning on port 135.

Figure 9: The Threat Visualizer reveals the action Antigena would have taken

When beaconing was later observed to bywce.payment.refinedwebs[.]com, this time over HTTP to /updateSoftwareVersion, RESPOND escalated its response by blocking the further C2 channels.

Figure 10: Antigena escalates its response

The vast majority of response tools rely on hard-coded, pre-defined rules, formulated as ‘If X, do Y’. This can lead to false positives that unnecessarily take devices offline and hamper productivity. Darktrace RESPOND's actions are proportionate, bespoke to the organization, and not created in advance. Darktrace Antigena autonomously chose what to block and the severity of the blocks based on the context of the intrusion, without a human pre-eminently hard-coding any commands or set responses.

Every response over the 48 hours was related to the incident – RESPOND did not try to take action on anything else during the intrusion period. It simply would have actioned a surgical response to contain the threat, while allowing the rest of the business to carry on as usual. There were a total of 59 actions throughout the incident time period – excluding the ‘Watched Domain Block’ actions shown below – which are used during incident response to proactively shut down C2 communication.

Figure 11: All Antigena action attempts during the intrusion period across the whole organization

RESPOND would have delivered those blocks via whatever integration is most suitable for the organization – whether that be Firewall integrations, NACL integrations or other native integrations. The technology would have blocked the malicious activity on the relevant ports and protocols for several hours – surgically interrupting the threat actors’ intrusion activity, thus preventing further escalation and giving the security team air cover.

Stopping WastedLocker ransomware before encryption ensues

This attack used many notable Tools, Techniques and Procedures (TTPs) to bypass signature-based tools. It took advantage of ‘Living off the Land’ techniques, including Windows Management Instrumentation (WMI), Powershell, and default admin credential use. Only one of the involved C2 domains had a single hit on Open Source Intelligence Lists (OSINT); the others were unknown at the time. The C2 was also encrypted with legitimate Thawte SSL Certificates.

For these reasons, it is plausible that without Darktrace in place, the ransomware would have been successful in encrypting files, preventing business operations at a critical time and possibly inflicting huge financial and reputational losses to the organization in question.

Darktrace’s AI detects and stops ransomware in its tracks without relying on threat intelligence. Ransomware has thrived this year, with attackers constantly coming up with new attack TTPs. However, the above threat find demonstrates that even targeted, sophisticated strains of ransomware can be stopped with AI technology.

Thanks to Darktrace analyst Signe Zaharka for her insights on the above threat find.

Learn more about Autonomous Response

Darktrace model detections:

  • Compliance / High Priority Compliance Model Breach
  • Compliance / Weak Active Directory Ticket Encryption
  • Anomalous Connection / Cisco Umbrella Block Page
  • Anomalous Server Activity / Anomalous External Activity from Critical Network Device
  • Compliance / Default Credential Usage
  • Compromise / Suspicious TLS Beaconing To Rare External
  • Anomalous Server Activity / Rare External from Server
  • Device / Lateral Movement and C2 Activity
  • Compromise / SSL Beaconing to Rare Destination
  • Device / New or Uncommon WMI Activity
  • Compromise / Watched Domain
  • Antigena / Network / External Threat / Antigena Watched Domain Block
  • Compromise / HTTP Beaconing to Rare Destination
  • Compromise / Slow Beaconing Activity To External Rare
  • Device / Multiple Lateral Movement Model Breaches
  • Compromise / High Volume of Connections with Beacon Score
  • Device / Large Number of Model Breaches
  • Compromise / Beaconing Activity To External Rare
  • Antigena / Network / Significant Anomaly / Antigena Controlled and Model Breach
  • Anomalous Connection / New or Uncommon Service Control
  • Antigena / Network / Significant Anomaly / Antigena Significant Anomaly from Client Block
  • Compromise / SSL or HTTP Beacon
  • Antigena / Network / External Threat / Antigena Suspicious Activity Block
  • Antigena / Network / Significant Anomaly / Antigena Breaches Over Time Block
  • Compromise / Sustained SSL or HTTP Increase
  • Unusual Activity / Unusual Internal Connections
  • Device / ICMP Address Scan

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
Max Heinemeyer
Global Field CISO

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October 20, 2025

Salty Much: Darktrace’s view on a recent Salt Typhoon intrusion

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What is Salt Typhoon?

Salt Typhoon represents one of the most persistent and sophisticated cyber threats targeting global critical infrastructure today. Believed to be linked to state-sponsored actors from the People’s Republic of China (PRC), this advanced persistent threat (APT) group has executed a series of high-impact campaigns against telecommunications providers, energy networks, and government systems—most notably across the United States.

Active since at least 2019, the group—also tracked as Earth Estries, GhostEmperor, and UNC2286—has demonstrated advanced capabilities in exploiting edge devices, maintaining deep persistence, and exfiltrating sensitive data across more than 80 countries. While much of the public reporting has focused on U.S. targets, Salt Typhoon’s operations have extended into Europe, the Middle East, and Africa (EMEA) where it has targeted telecoms, government entities, and technology firms. Its use of custom malware and exploitation of high-impact vulnerabilities (e.g., Ivanti, Fortinet, Cisco) underscores the strategic nature of its campaigns, which blend intelligence collection with geopolitical influence [1].

Leveraging zero-day exploits, obfuscation techniques, and lateral movement strategies, Salt Typhoon has demonstrated an alarming ability to evade detection and maintain long-term access to sensitive environments. The group’s operations have exposed lawful intercept systems, compromised metadata for millions of users, and disrupted essential services, prompting coordinated responses from intelligence agencies and private-sector partners worldwide. As organizations reassess their threat models, Salt Typhoon serves as a stark reminder of the evolving nature of nation-state cyber operations and the urgent need for proactive defense strategies.

Darktrace’s coverage

In this case, Darktrace observed activity in a European telecommunications organisation consistent with Salt Typhoon’s known tactics, techniques and procedures (TTPs), including dynamic-link library (DLL) sideloading and abuse of legitimate software for stealth and execution.

Initial access

The intrusion likely began with exploitation of a Citrix NetScaler Gateway appliance in the first week of July 2025. From there, the actor pivoted to Citrix Virtual Delivery Agent (VDA) hosts in the client’s Machine Creation Services (MCS) subnet. Initial access activities in the intrusion originated from an endpoint potentially associated with the SoftEther VPN service, suggesting infrastructure obfuscation from the outset.

Tooling

Darktrace subsequently observed the threat actor delivering a backdoor assessed with high confidence to be SNAPPYBEE (also known as Deed RAT) [2][3] to multiple Citrix VDA hosts. The backdoor was delivered to these internal endpoints as a DLL alongside legitimate executable files for antivirus software such as Norton Antivirus, Bkav Antivirus, and IObit Malware Fighter. This pattern of activity indicates that the attacker relied on DLL side-loading via legitimate antivirus software to execute their payloads. Salt Typhoon and similar groups have a history of employing this technique [4][5], enabling them to execute payloads under the guise of trusted software and bypassing traditional security controls.

Command-and-Control (C2)

The backdoor delivered by the threat actor leveraged LightNode VPS endpoints for C2, communicating over both HTTP and an unidentified TCP-based protocol. This dual-channel setup is consistent with Salt Typhoon’s known use of non-standard and layered protocols to evade detection. The HTTP communications displayed by the backdoor included POST requests with an Internet Explorer User-Agent header and Target URI patterns such as “/17ABE7F017ABE7F0”. One of the C2 hosts contacted by compromised endpoints was aar.gandhibludtric[.]com (38.54.63[.]75), a domain recently linked to Salt Typhoon [6].

Detection timeline

Darktrace produced high confidence detections in response to the early stages of the intrusion, with both the initial tooling and C2 activities being strongly covered by both investigations by Darktrace Cyber AI AnalystTM investigations and Darktrace models. Despite the sophistication of the threat actor, the intrusion activity identified and remediated before escalating beyond these early stages of the attack, with Darktrace’s timely high-confidence detections likely playing a key role in neutralizing the threat.

Cyber AI Analyst observations

Darktrace’s Cyber AI Analyst autonomously investigated the model alerts generated by Darktrace during the early stages of the intrusion. Through its investigations, Cyber AI Analyst discovered the initial tooling and C2 events and pieced them together into unified incidents representing the attacker’s progression.

Cyber AI Analyst weaved together separate events from the intrusion into broader incidents summarizing the attacker’s progression.
Figure 1: Cyber AI Analyst weaved together separate events from the intrusion into broader incidents summarizing the attacker’s progression.

Conclusion

Based on overlaps in TTPs, staging patterns, infrastructure, and malware, Darktrace assesses with moderate confidence that the observed activity was consistent with Salt Typhoon/Earth Estries (ALA GhostEmperor/UNC2286). Salt Typhoon continues to challenge defenders with its stealth, persistence, and abuse of legitimate tools. As attackers increasingly blend into normal operations, detecting behavioral anomalies becomes essential for identifying subtle deviations and correlating disparate signals. The evolving nature of Salt Typhoon’s tradecraft, and its ability to repurpose trusted software and infrastructure, ensures it will remain difficult to detect using conventional methods alone. This intrusion highlights the importance of proactive defense, where anomaly-based detections, not just signature matching, play a critical role in surfacing early-stage activity.

Credit to Nathaniel Jones (VP, Security & AI Strategy, FCISO), Sam Lister (Specialist Security Researcher), Emma Foulger (Global Threat Research Operations Lead), Adam Potter (Senior Cyber Analyst)

Edited by Ryan Traill (Analyst Content Lead)

Appendices

Indicators of Compromise (IoCs)

IoC-Type-Description + Confidence

89.31.121[.]101 – IP Address – Possible C2 server

hxxp://89.31.121[.]101:443/WINMM.dll - URI – Likely SNAPPYBEE download

b5367820cd32640a2d5e4c3a3c1ceedbbb715be2 - SHA1 – Likely SNAPPYBEE download

hxxp://89.31.121[.]101:443/NortonLog.txt - URI - Likely DLL side-loading activity

hxxp://89.31.121[.]101:443/123.txt - URI - Possible DLL side-loading activity

hxxp://89.31.121[.]101:443/123.tar - URI - Possible DLL side-loading activity

hxxp://89.31.121[.]101:443/pdc.exe - URI - Possible DLL side-loading activity

hxxp://89.31.121[.]101:443//Dialog.dat - URI - Possible DLL side-loading activity

hxxp://89.31.121[.]101:443/fltLib.dll - URI - Possible DLL side-loading activity

hxxp://89.31.121[.]101:443/DisplayDialog.exe - URI - Possible DLL side-loading activity

hxxp://89.31.121[.]101:443/DgApi.dll - URI - Likely DLL side-loading activity

hxxp://89.31.121[.]101:443/dbindex.dat - URI - Likely DLL side-loading activity

hxxp://89.31.121[.]101:443/1.txt - URI - Possible DLL side-loading activity

hxxp://89.31.121[.]101:443/imfsbDll.dll – Likely DLL side-loading activity

hxxp://89.31.121[.]101:443/imfsbSvc.exe - URI – Likely DLL side-loading activity

aar.gandhibludtric[.]com – Hostname – Likely C2 server

38.54.63[.]75 – IP – Likely C2 server

156.244.28[.]153 – IP – Possible C2 server

hxxp://156.244.28[.]153/17ABE7F017ABE7F0 - URI – Possible C2 activity

MITRE TTPs

Technique | Description

T1190 | Exploit Public-Facing Application - Citrix NetScaler Gateway compromise

T1105 | Ingress Tool Transfer – Delivery of backdoor to internal hosts

T1665 | Hide Infrastructure – Use of SoftEther VPN for C2

T1574.001 | Hijack Execution Flow: DLL – Execution of backdoor through DLL side-loading

T1095 | Non-Application Layer Protocol – Unidentified application-layer protocol for C2 traffic

T1071.001| Web Protocols – HTTP-based C2 traffic

T1571| Non-Standard Port – Port 443 for unencrypted HTTP traffic

Darktrace Model Alerts during intrusion

Anomalous File::Internal::Script from Rare Internal Location

Anomalous File::EXE from Rare External Location

Anomalous File::Multiple EXE from Rare External Locations

Anomalous Connection::Possible Callback URL

Antigena::Network::External Threat::Antigena Suspicious File Block

Antigena::Network::Significant Anomaly::Antigena Significant Server Anomaly Block

Antigena::Network::Significant Anomaly::Antigena Controlled and Model Alert

Antigena::Network::Significant Anomaly::Antigena Alerts Over Time Block

Antigena::Network::External Threat::Antigena File then New Outbound Block  

References

[1] https://www.cisa.gov/news-events/cybersecurity-advisories/aa25-239a

[2] https://www.trendmicro.com/en_gb/research/24/k/earth-estries.html

[3] https://www.trendmicro.com/content/dam/trendmicro/global/en/research/24/k/earth-estries/IOC_list-EarthEstries.txt

[4] https://www.trendmicro.com/en_gb/research/24/k/breaking-down-earth-estries-persistent-ttps-in-prolonged-cyber-o.html

[5] https://lab52.io/blog/deedrat-backdoor-enhanced-by-chinese-apts-with-advanced-capabilities/

[6] https://www.silentpush.com/blog/salt-typhoon-2025/

The content provided in this blog is published by Darktrace for general informational purposes only and reflects our understanding of cybersecurity topics, trends, incidents, and developments at the time of publication. While we strive to ensure accuracy and relevance, the information is provided “as is” without any representations or warranties, express or implied. Darktrace makes no guarantees regarding the completeness, accuracy, reliability, or timeliness of any information presented and expressly disclaims all warranties.

Nothing in this blog constitutes legal, technical, or professional advice, and readers should consult qualified professionals before acting on any information contained herein. Any references to third-party organizations, technologies, threat actors, or incidents are for informational purposes only and do not imply affiliation, endorsement, or recommendation.

Darktrace, its affiliates, employees, or agents shall not be held liable for any loss, damage, or harm arising from the use of or reliance on the information in this blog.

The cybersecurity landscape evolves rapidly, and blog content may become outdated or superseded. We reserve the right to update, modify, or remove any content.

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Nathaniel Jones
VP, Security & AI Strategy, Field CISO

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October 15, 2025

How a Major Civil Engineering Company Reduced MTTR across Network, Email and the Cloud with Darktrace

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Asking more of the information security team

“What more can we be doing to secure the company?” is a great question for any cyber professional to hear from their Board of Directors. After successfully defeating a series of attacks and seeing the potential for AI tools to supercharge incoming threats, a UK-based civil engineering company’s security team had the answer: Darktrace.

“When things are coming at you at machine speed, you need machine speed to fight it off – it’s as simple as that,” said their Information Security Manager. “There were incidents where it took us a few hours to get to the bottom of what was going on. Darktrace changed that.”

Prevention was also the best cure. A peer organization in the same sector was still in business continuity measures 18 months after an attack, and the security team did not want to risk that level of business disruption.

Legacy tools were not meeting the team’s desired speed or accuracy

The company’s native SaaS email platform took between two and 14 days to alert on suspicious emails, with another email security tool flagging malicious emails after up to 24 days. After receiving an alert, responses often took a couple of days to coordinate. The team was losing precious time.

Beyond long detection and response times, the old email security platform was no longer performing: 19% of incoming spam was missed. Of even more concern: 6% of phishing emails reached users’ inboxes, and malware and ransomware email was also still getting through, with 0.3% of such email-borne payloads reaching user inboxes.

Choosing Darktrace

“When evaluating tools in 2023, only Darktrace had what I was looking for: an existing, mature, AI-based cybersecurity solution. ChatGPT had just come out and a lot of companies were saying ‘AI this’ and ‘AI that’. Then you’d take a look, and it was all rules- and cases-based, not AI at all,” their Information Security Manager.

The team knew that, with AI-enabled attacks on the horizon, a cybersecurity company that had already built, fielded, and matured an AI-powered cyber defense would give the security team the ability to fend off machine-speed attacks at the same pace as the attackers.

Darktrace accomplishes this with multi-layered AI that learns each organization’s normal business operations. With this detailed level of understanding, Darktrace’s Self-Learning AI can recognize unusual activity that may indicate a cyber-attack, and works to neutralize the threat with precise response actions. And it does this all at machine speed and with minimal disruption.

On the morning the team was due to present its findings, the session was cancelled – for a good reason. The Board didn’t feel further discussion was necessary because the case for Darktrace was so conclusive. The CEO described the Darktrace option as ‘an insurance policy we can’t do without’.

Saving time with Darktrace / EMAIL

Darktrace / EMAIL reduced the discovery, alert, and response process from days or weeks to seconds .

Darktrace / EMAIL automates what was originally a time-consuming and repetitive process. The team has recovered between eight and 10 working hours a week by automating much of this process using / EMAIL.

Today, Darktrace / EMAIL prevents phishing emails from reaching employees’ inboxes. The volume of hostile and unsolicited email fell to a third of its original level after Darktrace / EMAIL was set up.

Further savings with Darktrace / NETWORK and Darktrace / IDENTITY

Since its success with Darktrace / EMAIL, the company adopted two more products from the Darktrace ActiveAI Security Platform – Darktrace / NETWORK and Darktrace / IDENTITY.

These have further contributed to cost savings. An initial plan to build a 24/7 SOC would have required hiring and retaining six additional analysts, rather than the two that currently use Darktrace, costing an additional £220,000 per year in salary. With Darktrace, the existing analysts have the tools needed to become more effective and impactful.

An additional benefit: Darktrace adoption has lowered the company’s cyber insurance premiums. The security team can reallocate this budget to proactive projects.

Detection of novel threats provides reassurance

Darktrace’s unique approach to cybersecurity added a key benefit. The team’s previous tool took a rules-based approach – which was only good if the next attack featured the same characteristics as the ones on which the tool was trained.

“Darktrace looks for anomalous behavior, and we needed something that detected and responded based on use cases, not rules that might be out of date or too prescriptive,” their Information Security Manager. “Our existing provider could take a couple of days to update rules and signatures, and in this game, speed is of the essence. Darktrace just does everything we need - without delay.”

Where rules-based tools must wait for a threat to emerge before beginning to detect and respond to it, Darktrace identifies and protects against unknown and novel threats, speeding identification, response, and recovery, minimizing business disruption as a result.

Looking to the future

With Darktrace in place, the UK-based civil engineering company team has reallocated time and resources usually spent on detection and alerting to now tackle more sophisticated, strategic challenges. Darktrace has also equipped the team with far better and more regularly updated visibility into potential vulnerabilities.

“One thing that frustrates me a little is penetration testing; our ISO accreditation mandates a penetration test at least once a year, but the results could be out of date the next day,” their Information Security Manager. “Darktrace / Proactive Exposure Management will give me that view in real time – we can run it daily if needed - and that’s going to be a really effective workbench for my team.”

As the company looks to further develop its security posture, Darktrace remains poised to evolve alongside its partner.

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