
Rhysida Ransomware: Healthcare Network Intrusion
A Rhysida ransomware affiliate phishes a healthcare staff member's VPN credentials and exploits a stale MFA exemption to breach a regional medical center. Using a Cobalt Strike beacon and built-in Windows tools, the attacker extracts all domain credentials, exfiltrates patient records for double extortion, and deploys the encryptor estate-wide. Trace the kill chain from the first failed VPN login to the final ransom note.
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Investigation Tasks
Complete each task by investigating alerts and submitting your findings.
Establish the entry point
40Before the clinical network can be trusted again, you need to know exactly how the attacker got in. The incident started with a remote-access session that should not have been permitted. Work out which account was used and why the normal second-factor check did not stop it.
Attribute the first successful tunnel
40The account that got in had two failed attempts before it succeeded. Separate those from the background of normal staff VPN sessions and identify the external address that established the malicious tunnel.
Find the credential theft method
50Once on the domain controller, the attacker extracted every domain password hash in a way that avoided touching the process most EDRs watch. Identify the ATT&CK technique that describes this method.
Locate the command-and-control channel
45The attacker ran a persistent beacon on the jump host throughout the intrusion. Pinpoint the external address it was calling home to.
Track the data out
45Before the encryptor ran, a large outbound transfer moved patient records off the network. Identify the external IP address that received the stolen data.
Name the privileged account used post-DC
45After extracting domain credentials from the DC, the attacker began moving laterally with a different account. Identify that account.
Classify the pre-encryption disruption
50In the hour before encryption, the attacker ran a sequence of operations designed to ensure recovery would be impossible. Identify the MITRE ATT&CK technique that covers the core goal of that sequence.
7 tasks · 315 points total
Training Tools
Skills You'll Build
Complex multi-stage investigations. Realistic noise, ambiguous indicators, lateral movement.
Prerequisites
- Basic understanding of security alerts
- Experience with log analysis tools
- Familiarity with SIEM concepts
- Familiarity with XDR concepts
- Familiarity with Firewall concepts
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