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March 18, 2020

5 Security Risks Companies Face Transitioning to Remote Work

Discover 5 security risks companies face with remote work employees. Protect against email scams, weakened security controls, errors, and insider threats.
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
Andrew Tsonchev
VP, Security & AI Strategy, Field CISO
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18
Mar 2020

As we all adjust to working remotely, security teams across the world are grappling with a very serious challenge. Almost overnight our companies have changed. Well established procedures are being rewritten, best practices quickly rethought, and policies stretched to breaking point.

Business transformation is always a security risk. New technology and working practices need new security measures; but normally this risk is managed carefully, and over time. COVID-19 has not afforded us that luxury. For some businesses the scale and speed of this change will be unprecedented. It is also very public; attackers are aware of the situation and already exploiting it. Below are some of the most serious threats that security teams will face over the coming weeks.

1. Email scams

Change brings novelty, and novelty brings opportunity for scammers. In the last 48 hours, internal security teams will have been racing to roll out essential remote working tools. Links to download new software, changes to how we authenticate services. When you do not know what to expect, employee training on spotting social engineering goes out the window. Both employees and IT departments should be wary of unexpected calls and requests:

“Hi, I’m calling from IT, can you please read out your 2FA code to me to confirm that you have been transitioned to the new Duo system?”

“Hi, I’ve forgotten my O365 password, can you please email a reset code to my personal Gmail?”

Such requests may be legitimate and may need to be resolved outside normal channels. The onus will be on individuals to be cautious, apply common sense and validate as appropriate.

There will also be ample opportunity for spear phishers to impersonate third-parties and clients:

“Hi John, I need to reschedule our meeting next week to be remote. Please see the link below for an invite to the Zoom call.”

These risks will be exacerbated by the simultaneous relaxing of security controls in order to facilitate the use of non-standard web conferencing software and the sharing of files by email. Attackers will have both the opportunity and the means.

2. Weakened security controls

The weakening of security controls goes far beyond relaxing firewall rules and email policy. Many existing layers of security will not apply to remote workers. Employees suddenly taking their work computer home with them will find themselves stripped of protection as they trade the office network for their home Wi-Fi. Without internet proxy, NAC, IDS and NGFW, client devices will now be sitting exposed on potentially unsecured networks amongst potentially compromised devices. Endpoint security will have to bear the full brunt of protection.

Internal network security may be compromised as well; employees might need access to resources previously only accessible on a wired network in one location. To make it reachable over VPN, internal segmentation might need to be flattened. This will open the door to malware spread and lateral movement. Client certificate authentication protecting web services might need to be turned off to enable BYOD working for employees that don’t have a company laptop.

These changes must be scrupulously logged, and dependencies understood. The extra weight will have to be carried elsewhere: perhaps host AV policies can be tightened to compensate for lack of network protection, perhaps employee devices can be reconfigured to use a secure external DNS provider instead of the on-prem DNS server.

3. Attacks on remote-working infrastructure

Beyond the weakening of existing controls, spinning up new infrastructure will bring fresh risks. In January we saw a spate of attacks on web-facing Citrix infrastructure. Companies will be rapidly deploying VPN gateways, transitioning to Sharepoint and expanding their internet-facing perimeter. This rapidly increased attack surface will need monitoring and protecting. Security teams should be on heightened alert for brute force and server-side attacks. DDoS protection will also become more important than ever; for many companies this will be the first time that a DDoS attack could cripple their business by preventing remote workers from accessing services over the internet. We should expect to see a sharp rise in both of these forms of attack immediately.

4. Errors and creative solutions

“Put it in an S3 bucket.”

“Let’s use join.me instead.”

“I’ll send it to you over WeTransfer.”

Both IT, and individual employees, will face blockers. There won’t be an authorized solution for their needs, and those needs may well be extremely urgent. At a time when businesses are extremely worried about their financial position and ability to operate, there will be pressure to throw caution to the wind and protect ‘business as usual’. This pressure may even come from the top. Security leadership must do the best they can to both push back against rash decisions and provide creative solutions.

Well-meaning employees will get creative, and responsibility will be delegated to team leaders to “do what it takes”. It may be impossible for security to police this centrally but monitoring vigilance will be required to spot risky behavior and non-compliance. This is easier said than done; the SOC will be asked to monitor for incidents in a sea of change. Existing use-cases and rules will not apply, and companies will need a more proactive and dynamic approach to detection and response.

5. Malicious insiders and malicious housemates

Unfortunately, there will be some within our companies that want to kick us while we are down. Sudden remote working is a godsend to malicious insiders. Data can now be easily taken from a company device over USB within the privacy of their own home. Security monitoring may be crippled or disabled entirely. This risk is harder to address. It may not be eliminable, but it can be balanced against the need for productivity and access to data.

We should also be wary of those around us. We all hope we can trust the people we live with. But from a company perspective, employee homes are zero-trust environments. Confidential conversations will now be conducted within range of eavesdroppers. Intellectual property will be visible on screens and monitors in living rooms around the world. This risk is greater for younger demographics likely to be house-sharing, but it remains for all workers; delivery personnel, visitors to the house – they could all potentially steal a company laptop from the kitchen room table. Education of employees in particular risk groups will be key.

Finding direction in a sea of digital change

All of the above changes and risks create a monitoring nightmare for SOCs. We are entering into a period of digital unknown, where change will be the new normal. Data flows and topology will change. New technology and services will be deployed. Logging formats will be different. The SIEM use-cases that took 12 months to develop will need to be scrapped overnight. For the next few weeks, business practice will shift rapidly.

Static defenses and rules will not be able to keep up, no matter how diligently and rapidly we rewrite them. How will you spot a malicious login attempt to O365 in your audit logs now that connections are coming from thousands of different locations around the world? Companies need to leverage technology that can allow them to continue to operate amidst uncertainty without choking productivity at this critical time. More critical still, containing those threats is of paramount importance – it won’t be feasible to entirely quarantine an infected machine if it cannot be re-imaged or replaced for days.

AI systems that can continuously evolve and adapt to change will provide the best chance of detecting misconfigurations, attacks, and risky behavior – when you don’t know what to look for, you need technology that is able to identify patterns and quantify risks for you. Autonomous Response technology can also surgically intervene to halt malicious activity when teams can’t be there to stop it, protecting devices and systems whilst allowing essential operations to continue unaffected.

Evolutions: Meeting the challenge head-on

Confronting these threats will not be easy. It will require a mixture of hard work, creativity, and new technology, alongside an openness to new ways of working and a willingness to embrace dynamic, proactive defense, instead of traditional rigid policies. However, placing trust in defensive systems to autonomously protect employees will be the single most effective way of maintaining resilience and security when our static defenses have failed us.

At Darktrace we are working hard to help our customers get even more value from their Cyber AI platform throughout this difficult time, and ease workloads of busy security teams. We know that with the right tools and technologies – from Autonomous Response and Cyber AI Analyst, through to the Darktrace Mobile App – these teams will be able to navigate these stormy waters. In this unprecedented period of uncertainty, the need for security that evolves in step with your changing digital business has never been greater.

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
Andrew Tsonchev
VP, Security & AI Strategy, Field CISO

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May 16, 2025

Catching a RAT: How Darktrace neutralized AsyncRAT

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What is a RAT?

As the proliferation of new and more advanced cyber threats continues, the Remote Access Trojan (RAT) remains a classic tool in a threat actor's arsenal. RATs, whether standardized or custom-built, enable attackers to remotely control compromised devices, facilitating a range of malicious activities.

What is AsyncRAT?

Since its first appearance in 2019, AsyncRAT has become increasingly popular among a wide range of threat actors, including cybercriminals and advanced persistent threat (APT) groups.

Originally available on GitHub as a legitimate tool, its open-source nature has led to widespread exploitation. AsyncRAT has been used in numerous campaigns, including prolonged attacks on essential US infrastructure, and has even reportedly penetrated the Chinese cybercriminal underground market [1] [2].

How does AsyncRAT work?

Original source code analysis of AsyncRAT demonstrates that once installed, it establishes persistence via techniques such as creating scheduled tasks or registry keys and uses SeDebugPrivilege to gain elevated privileges [3].

Its key features include:

  • Keylogging
  • File search
  • Remote audio and camera access
  • Exfiltration techniques
  • Staging for final payload delivery

These are generally typical functions found in traditional RATs. However, it also boasts interesting anti-detection capabilities. Due to the popularity of Virtual Machines (VM) and sandboxes for dynamic analysis, this RAT checks for the manufacturer via the WMI query 'Select * from Win32_ComputerSystem' and looks for strings containing 'VMware' and 'VirtualBox' [4].

Darktrace’s coverage of AsyncRAT

In late 2024 and early 2025, Darktrace observed a spike in AsyncRAT activity across various customer environments. Multiple indicators of post-compromise were detected, including devices attempting or successfully connecting to endpoints associated with AsyncRAT.

On several occasions, Darktrace identified a clear association with AsyncRAT through the digital certificates of the highlighted SSL endpoints. Darktrace’s Real-time Detection effectively identified and alerted on suspicious activities related to AsyncRAT. In one notable incident, Darktrace’s Autonomous Response promptly took action to contain the emerging threat posed by AsyncRAT.

AsyncRAT attack overview

On December 20, 2024, Darktrace first identified the use of AsyncRAT, noting a device successfully establishing SSL connections to the uncommon external IP 185.49.126[.]50 (AS199654 Oxide Group Limited) via port 6606. The IP address appears to be associated with AsyncRAT as flagged by open-source intelligence (OSINT) sources [5]. This activity triggered the device to alert the ‘Anomalous Connection / Rare External SSL Self-Signed' model.

Model alert in Darktrace / NETWORK showing the repeated SSL connections to a rare external Self-Signed endpoint, 185.49.126[.]50.
Figure 1: Model alert in Darktrace / NETWORK showing the repeated SSL connections to a rare external Self-Signed endpoint, 185.49.126[.]50.

Following these initial connections, the device was observed making a significantly higher number of connections to the same endpoint 185.49.126[.]50 via port 6606 over an extended period. This pattern suggested beaconing activity and triggered the 'Compromise/Beaconing Activity to External Rare' model alert.

Further analysis of the original source code, available publicly, outlines the default ports used by AsyncRAT clients for command-and-control (C2) communications [6]. It reveals that port 6606 is the default port for creating a new AsyncRAT client. Darktrace identified both the Certificate Issuer and the Certificate Subject as "CN=AsyncRAT Server". This SSL certificate encrypts the packets between the compromised system and the server. These indicators of compromise (IoCs) detected by Darktrace further suggest that the device was successfully connecting to a server associated with AsyncRAT.

Model alert in Darktrace / NETWORK displaying the Digital Certificate attributes, IP address and port number associated with AsyncRAT.
Figure 2: Model alert in Darktrace / NETWORK displaying the Digital Certificate attributes, IP address and port number associated with AsyncRAT.
Darktrace’s detection of repeated connections to the suspicious IP address 185.49.126[.]50 over port 6606, indicative of beaconing behavior.
Figure 3: Darktrace’s detection of repeated connections to the suspicious IP address 185.49.126[.]50 over port 6606, indicative of beaconing behavior.
Darktrace's Autonomous Response actions blocking the suspicious IP address,185.49.126[.]50.
Figure 4: Darktrace's Autonomous Response actions blocking the suspicious IP address,185.49.126[.]50.

A few days later, the same device was detected making numerous connections to a different IP address, 195.26.255[.]81 (AS40021 NL-811-40021), via various ports including 2106, 6606, 7707, and 8808. Notably, ports 7707 and 8808 are also default ports specified in the original AsyncRAT source code [6].

Darktrace’s detection of connections to the suspicious endpoint 195.26.255[.]81, where the default ports (6606, 7707, and 8808) for AsyncRAT were observed.
Figure 5: Darktrace’s detection of connections to the suspicious endpoint 195.26.255[.]81, where the default ports (6606, 7707, and 8808) for AsyncRAT were observed.

Similar to the activity observed with the first endpoint, 185.49.126[.]50, the Certificate Issuer for the connections to 195.26.255[.]81 was identified as "CN=AsyncRAT Server". Further OSINT investigation confirmed associations between the IP address 195.26.255[.]81 and AsyncRAT [7].

Darktrace's detection of a connection to the suspicious IP address 195.26.255[.]81 and the domain name identified under the common name (CN) of a certificate as AsyncRAT Server
Figure 6: Darktrace's detection of a connection to the suspicious IP address 195.26.255[.]81 and the domain name identified under the common name (CN) of a certificate as AsyncRAT Server.

Once again, Darktrace's Autonomous Response acted swiftly, blocking the connections to 195.26.255[.]81 throughout the observed AsyncRAT activity.

Figure 7: Darktrace's Autonomous Response actions were applied against the suspicious IP address 195.26.255[.]81.

A day later, Darktrace again alerted to further suspicious activity from the device. This time, connections to the suspicious endpoint 'kashuub[.]com' and IP address 191.96.207[.]246 via port 8041 were observed. Further analysis of port 8041 suggests it is commonly associated with ScreenConnect or Xcorpeon ASIC Carrier Ethernet Transport [8]. ScreenConnect has been observed in recent campaign’s where AsyncRAT has been utilized [9]. Additionally, one of the ASN’s observed, namely ‘ASN Oxide Group Limited’, was seen in both connections to kashuub[.]com and 185.49.126[.]50.

This could suggest a parallel between the two endpoints, indicating they might be hosting AsyncRAT C2 servers, as inferred from our previous analysis of the endpoint 185.49.126[.]50 and its association with AsyncRAT [5]. OSINT reporting suggests that the “kashuub[.]com” endpoint may be associated with ScreenConnect scam domains, further supporting the assumption that the endpoint could be a C2 server.

Darktrace’s Autonomous Response technology was once again able to support the customer here, blocking connections to “kashuub[.]com”. Ultimately, this intervention halted the compromise and prevented the attack from escalating or any sensitive data from being exfiltrated from the customer’s network into the hands of the threat actors.

Darktrace’s Autonomous Response applied a total of nine actions against the IP address 191.96.207[.]246 and the domain 'kashuub[.]com', successfully blocking the connections.
Figure 8: Darktrace’s Autonomous Response applied a total of nine actions against the IP address 191.96.207[.]246 and the domain 'kashuub[.]com', successfully blocking the connections.

Due to the popularity of this RAT, it is difficult to determine the motive behind the attack; however, from existing knowledge of what the RAT does, we can assume accessing and exfiltrating sensitive customer data may have been a factor.

Conclusion

While some cybercriminals seek stability and simplicity, openly available RATs like AsyncRAT provide the infrastructure and open the door for even the most amateur threat actors to compromise sensitive networks. As the cyber landscape continually shifts, RATs are now being used in all types of attacks.

Darktrace’s suite of AI-driven tools provides organizations with the infrastructure to achieve complete visibility and control over emerging threats within their network environment. Although AsyncRAT’s lack of concealment allowed Darktrace to quickly detect the developing threat and alert on unusual behaviors, it was ultimately Darktrace Autonomous Response's consistent blocking of suspicious connections that prevented a more disruptive attack.

Credit to Isabel Evans (Cyber Analyst), Priya Thapa (Cyber Analyst) and Ryan Traill (Analyst Content Lead)

Appendices

  • Real-time Detection Models
       
    • Compromise / Suspicious SSL Activity
    •  
    • Compromise / Beaconing Activity To      External Rare
    •  
    • Compromise / High Volume of      Connections with Beacon Score
    •  
    • Anomalous Connection / Suspicious      Self-Signed SSL
    •  
    • Compromise / Sustained SSL or HTTP      Increase
    •  
    • Compromise / SSL Beaconing to Rare      Destination
    •  
    • Compromise / Suspicious Beaconing      Behaviour
    •  
    • Compromise / Large Number of      Suspicious Failed Connections
  •  
  • Autonomous     Response Models
       
    • Antigena / Network / Significant      Anomaly / Antigena Controlled and Model Alert
    •  
    • Antigena / Network / Significant      Anomaly / Antigena Enhanced Monitoring from Client Block

List of IoCs

·     185.49.126[.]50 - IP – AsyncRAT C2 Endpoint

·     195.26.255[.]81 – IP - AsyncRAT C2 Endpoint

·      191.96.207[.]246 – IP – Likely AsyncRAT C2 Endpoint

·     CN=AsyncRAT Server - SSL certificate - AsyncRATC2 Infrastructure

·      Kashuub[.]com– Hostname – Likely AsyncRAT C2 Endpoint

MITRE ATT&CK Mapping:

Tactic –Technique – Sub-Technique  

 

Execution– T1053 - Scheduled Task/Job: Scheduled Task

DefenceEvasion – T1497 - Virtualization/Sandbox Evasion: System Checks

Discovery– T1057 – Process Discovery

Discovery– T1082 – System Information Discovery

LateralMovement - T1021.001 - Remote Services: Remote Desktop Protocol

Collection/ Credential Access – T1056 – Input Capture: Keylogging

Collection– T1125 – Video Capture

Commandand Control – T1105 - Ingress Tool Transfer

Commandand Control – T1219 - Remote Access Software

Exfiltration– T1041 - Exfiltration Over C2 Channel

 

References

[1]  https://blog.talosintelligence.com/operation-layover-how-we-tracked-attack/

[2] https://intel471.com/blog/china-cybercrime-undergrond-deepmix-tea-horse-road-great-firewall

[3] https://www.attackiq.com/2024/08/01/emulate-asyncrat/

[4] https://www.fortinet.com/blog/threat-research/spear-phishing-campaign-with-new-techniques-aimed-at-aviation-companies

[5] https://www.virustotal.com/gui/ip-address/185.49.126[.]50/community

[6] https://dfir.ch/posts/asyncrat_quasarrat/

[7] https://www.virustotal.com/gui/ip-address/195.26.255[.]81

[8] https://www.speedguide.net/port.php?port=8041

[9] https://www.esentire.com/blog/exploring-the-infection-chain-screenconnects-link-to-asyncrat-deployment

[10] https://scammer.info/t/taking-out-connectwise-sites/153479/518?page=26

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About the author
Isabel Evans
Cyber Analyst

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May 13, 2025

Revolutionizing OT Risk Prioritization with Darktrace 6.3

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Powering smarter protection for industrial systems

In industrial environments, security challenges are deeply operational. Whether you’re running a manufacturing line, a power grid, or a semiconductor fabrication facility (fab), you need to know: What risks can truly disrupt my operations, and what should I focus on first?

Teams need the right tools to shift from reactive defense, constantly putting out fires, to proactively thinking about their security posture. However, most OT teams are stuck using IT-centric tools that don’t speak the language of industrial systems, are consistently overwhelmed with static CVE lists, and offer no understanding of OT-specific protocols. The result? Compliance gaps, siloed insights, and risk models that don’t reflect real-world exposure, making risk prioritization seem like a luxury.

Darktrace / OT 6.3 was built in direct response to these challenges. Developed in close collaboration with OT operators and engineers, this release introduces powerful upgrades that deliver the context, visibility, and automation security teams need, without adding complexity. It’s everything OT defenders need to protect critical operations in one platform that understands the language of industrial systems.

additions to darktrace / ot 6/3

Contextual risk modeling with smarter Risk Scoring

Darktrace / OT 6.3 introduces major upgrades to OT Risk Management, helping teams move beyond generic CVE lists with AI-driven risk scoring and attack path modeling.

By factoring in real-world exploitability, asset criticality, and operational context, this release delivers a more accurate view of what truly puts critical systems at risk.

The platform now integrates:

  • CISA’s Known Exploited Vulnerabilities (KEV) database
  • End-of-life status for legacy OT devices
  • Firewall misconfiguration analysis
  • Incident response plan alignment

Most OT environments are flooded with vulnerability data that lacks context. CVE scores often misrepresent risk by ignoring how threats move through the environment or whether assets are even reachable. Firewalls are frequently misconfigured or undocumented, and EOL (End of Life) devices, some of the most vulnerable, often go untracked.

Legacy tools treat these inputs in isolation. Darktrace unifies them, showing teams exactly which attack paths adversaries could exploit, mapped to the MITRE ATT&CK framework, with visibility into where legacy tech increases exposure.

The result: teams can finally focus on the risks that matter most to uptime, safety, and resilience without wasting resources on noise.

Automating compliance with dynamic IEC-62443 reporting

Darktrace / OT now includes a purpose-built IEC-62443-3-3 compliance module, giving industrial teams real-time visibility into their alignment with regulatory standards. No spreadsheets required!

Industrial environments are among the most heavily regulated. However, for many OT teams, staying compliant is still a manual, time-consuming process.

Darktrace / OT introduces a dedicated IEC-62443-3-3 module designed specifically for industrial environments. Security and operations teams can now map their security posture to IEC standards in real time, directly within the platform. The module automatically gathers evidence across all four security levels, flags non-compliance, and generates structured reports to support audit preparation, all in just a few clicks.Most organizations rely on spreadsheets or static tools to track compliance, without clear visibility into which controls meet standards like IEC-62443. The result is hidden gaps, resource-heavy audits, and slow remediation cycles.

Even dedicated compliance tools are often built for IT, require complex setup, and overlook the unique devices found in OT environments. This leaves teams stuck with fragmented reporting and limited assurance that their controls are actually aligned with regulatory expectations.

By automating compliance tracking, surfacing what matters most, and being purpose built for industrial environments, Darktrace / OT empowers organizations to reduce audit fatigue, eliminate blind spots, and focus resources where they’re needed most.

Expanding protocol visibility with deep insights for specialized OT operations

Darktrace has expanded its Deep Packet Inspection (DPI) capabilities to support five industry-specific protocols, across healthcare, semiconductor manufacturing, and ABB control systems.

The new protocols build on existing capabilities across all OT industry verticals and protocol types to ensure the Darktrace Self-Learning AI TM can learn intelligently about even more assets in complex industrial environments. By enabling native, AI-driven inspection of these protocols, Darktrace can identify both security threats and operational issues without relying on additional appliances or complex integrations.

Most security platforms lack native support for industry-specific protocols, creating critical visibility gaps in customer environments like healthcare, semiconductor manufacturing, and ABB-heavy industrial automation. Without deep protocol awareness, organizations struggle to accurately identify specialized OT and IoT assets, detect malicious activity concealed within proprietary protocol traffic, and generate reliable device risk profiles due to insufficient telemetry.

These blind spots result in incomplete asset inventories, and ultimately, flawed risk posture assessments which over-index for CVE patching and legacy equipment.

By combining protocol-aware detection with full-stack visibility across IT, OT, and IoT, Darktrace’s AI can correlate anomalies across domains. For example, connecting an anomaly from a Medical IoT (MIoT) device with suspicious behavior in IT systems, providing actionable, contextual insights other solutions often miss.

Conclusion

Together, these capabilities take OT security beyond alert noise and basic CVE matching, delivering continuous compliance, protocol-aware visibility, and actionable, prioritized risk insights, all inside a single, unified platform built for the realities of industrial environments.

[related-resource]

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About the author
Pallavi Singh
Product Marketing Manager, OT Security & Compliance
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