Triskele Labs Blog

Kairos: The Extortion Group Changing the Ransomware Playbook

Written by Mike Varley | Feb 18, 2026 3:10:33 AM

Prepared by: Mike Varley, DFIR Analyst | Last update: 18 February 2026

What a recent intrusion reveals about the shift from encryption to data-driven pressure

In early 2025, reports emerged of an Australian hospitality group confirming a cyber incident linked to the Kairos ransomware operation. Unlike traditional ransomware attacks that encrypt systems and demand payment for decryption keys, Kairos is part of a growing wave of threat actors who focus on stealing sensitive information and using it as leverage.

Triskele Labs investigated a Kairos-linked intrusion in 2024, gaining direct visibility into how the group operates. The findings offer a clear reminder that modern extortion tactics are often quiet, targeted, and designed to apply pressure without disrupting business operations.

 

How the Attack Began

In the case investigated by Triskele Labs, the attacker gained access through an externally exposed Remote Desktop Gateway. A generic user account was compromised, with the password assessed as vulnerable to password spraying. There was no multi-factor authentication (MFA) in place, and access was not restricted through a VPN. In practical terms, the door was left unlocked. Once valid credentials were obtained, the attacker was able to log in directly without triggering strong security barriers.

This method reflects a broader trend: attackers are increasingly exploiting exposed services and weak authentication controls rather than relying on complex technical exploits.

 

What Happened Inside the Network

After gaining access, the attacker attempted to strengthen their position by harvesting credentials and exploring the internal environment. Tools commonly used in post-compromise activity were deployed to attempt privilege escalation and internal movement.

While lateral movement attempts were made using Remote Desktop, SMB and PowerShell, no successful widespread movement was observed in this instance.

However, internal password spraying activity continued, indicating an effort to expand access.

Importantly, the attacker also cleared Windows Event Logs to reduce visibility and complicate forensic investigation. This step is a common tactic designed to delay detection and limit evidence.

 

Data Theft Without Disruption

The defining feature of Kairos’ approach is what they do not do.

There was no encryption deployed, systems were not locked and operations were not deliberately disrupted.

Instead, the attacker staged and exfiltrated selected data using a legitimate file transfer tool (RClone), transferring it via SFTP to an overseas hosting provider. The data targeted was specific: PDFs, Word documents and other common business document formats, rather than a wholesale extraction of all available data.

This precision suggests a deliberate strategy. By avoiding operational damage, attackers reduce immediate detection and position themselves to apply pressure later through extortion threats.

 

Psychological Pressure as a Weapon

Rather than deploying ransomware, Kairos used internal communications as a pressure tactic. Emails were sent from a compromised account via Outlook to notify staff of the breach and data theft. There were also attempts to make contact by telephone. This tactic serves multiple purposes; creates internal panic and uncertainty, accelerates executive awareness and pressures organisations to respond quickly.

The threat is not system downtime it's reputational damage and public data exposure. This is known as a single-extortion model, where the leverage lies entirely in the stolen data.

 

What Makes Kairos Different

Kairos demonstrates a shift in how extortion operations are conducted:

  • Reliance on valid credentials rather than noisy exploits

  • Use of legitimate remote access services

  • Focused data exfiltration rather than mass encryption

  • Psychological manipulation through direct communication

They are not necessarily loud or destructive. In fact, the lack of disruption can delay detection and increase the strategic impact of the breach.

Practical Lessons for Organisations

The intrusion investigated by Triskele Labs highlights several practical controls that materially reduce risk

  • Enforce strong password policies and deploy MFA across all remote access services
  • Restrict or remove externally exposed RDP and RDG services
  • Monitor PowerShell usage and outbound SFTP activity
  • Maintain strong log retention and endpoint detection capabilities

Most importantly, organisations should recognise that ransomware is no longer defined by encryption alone. Data theft and extortion now sit at the centre of many modern attacks.

The Kairos model reinforces a clear message: attackers do not need to shut down your business to cause serious harm. Quiet access, selective data theft, and calculated pressure can be just as damaging.

 

Technical Appendix: Tools, Techniques and MITRE ATT&CK Mapping

The following technical observations were identified during the Triskele Labs investigation of a Kairos-linked intrusion:

These details are aligned to the MITRE ATT&CK framework to support security and detection teams.

Initial Access

Observed Activity
  • External Remote Desktop Gateway (RDG) exposed to the internet
  • Use of valid domain credentials
  • Password assessed as vulnerable to spraying
  • No MFA or VPN enforcement
MITRE ATT&CK Mapping
  • T1133 – External Remote Services
  • T1078.002 – Valid Accounts: Domain Accounts

The attacker did not exploit software vulnerabilities; instead, they leveraged weak authentication controls.

Credential Access and Privilede Escalation

Tools Used 
  • Rubeus (Kerberos interaction and ticket manipulation tool)

Observed Activity
  • Attempts to access LSASS memory
  • Attempts to access NTDS data
  • Kerberos ticket manipulation (Kerberoasting-style activity)
  • Internal brute-force attempts against additional accounts
MITRE ATT&CK Mapping
  • T1003.001 – OS Credential Dumping: LSASS Memory
  • T1003.003 – OS Credential Dumping: NTDS
  • T1558.003 – Steal or Forge Kerberos Tickets

This phase focused on expanding privileges to enable broader access across the domain.

Discovery and Lateral Movement

Techniques Attempted
  • Remote Desktop Protocol (RDP)
  • Server Message Block (SMB)
  • PowerShell Invoke-Command
  • Network share and service enumeration
  • Domain account discovery
MITRE ATT&CK Mapping
  • T1021.001 – Remote Services: Remote Desktop Protocol
  • T1021.004 – Remote Services: SMB
  • T1046 – Network Service Discovery
  • T1135 – Network Share Discovery
  • T1087.002 – Account Discovery: Domain Account

While large-scale lateral movement was not confirmed in this case, the techniques are consistent with domain-wide expansion attempts.

Defence Evasion

Observed Activity
  • Clearing Windows Event Logs via PowerShell

MITRE ATT&CK Mapping
  • T1070.001 – Indicator Removal on Host: Clear Windows Event Logs
  • T1562.001 – Impair Defences: Disable or Modify Tools

Log clearing is a deliberate attempt to reduce forensic visibility and delay detection.

Data Staging and Exfiltration

Tools Used
  • RClone (legitimate file transfer utility)
Observed Activity
  • Data staging prior to transfer
  • Exfiltration over SFTP
  • Transfer to infrastructure hosted in Ukraine
  • Selective targeting of PDF, DOCX and common business document types
MITRE ATT&CK Mapping
  • T1074 – Data Staged
  • T1039 – Data from Network Shared Drive
  • T1048 – Exfiltration Over Alternative Protocol
  • T1567.002 – Exfiltration to Cloud Storage

The use of legitimate tooling and alternative protocols reduces the likelihood of detection where outbound traffic monitoring is limited.

Impact and Coercion

Observed Activity
  • Internal emails sent from compromised Outlook account
  • Telephone contact attempts
  • No encryption deployed
MITRE ATT&CK Mapping
  • T1491.001 – Defacement: Internal Defacement

Rather than encrypting systems, Kairos relies on data theft and psychological pressure to compel payment — a deliberate single-extortion model.

This mapping reinforces that Kairos does not rely on novel exploits. Instead, the group combines valid credentials, legitimate administrative tooling, and established ATT&CK techniques in a disciplined and controlled manner designed to minimise noise while maximising leverage.