Rhysida Ransomware Leaks 6TB of Berlin State Data After 30 BTC Ransom Refusal — Detection and Hardening Guide

Berlin refused to pay a 30 Bitcoin ransom. The Rhysida ransomware group responded by dumping nearly six terabytes of sensitive state administration and national defense data onto the dark web. This is the nightmare scenario every government CISO games out on paper — and it just played out in production.

This incident matters far beyond Germany. Rhysida has been one of the most active ransomware operations targeting public sector and critical infrastructure organizations, and this leak demonstrates the group's willingness to follow through on double-extortion threats even against well-resourced government targets. If your organization handles citizen data, defense-adjacent information, or regulated records of any kind, you are operating in Rhysida's target profile.

The defensive lesson here is blunt: by the time you're deciding whether to pay a ransom, you have already lost control of the outcome. The only decision point that matters is the one months earlier — when you either did or did not build the detection and containment capability to catch the intrusion before encryption and exfiltration.

What Happened

According to reporting on the incident, the Rhysida ransomware group breached Berlin state systems, exfiltrated approximately 6TB of data spanning state administration files and national defense-related material, and demanded 30 BTC. When Berlin refused to pay, the group published the stolen data on its dark web leak site — the standard Rhysida double-extortion playbook: encrypt what you can, steal everything, and monetize refusal through public exposure.

Six terabytes is not an opportunistic smash-and-grab. That volume of exfiltration indicates sustained dwell time — likely weeks — with staging, archiving, and bulk transfer of data over channels that apparently went undetected. That is the detection failure at the heart of this story.

Technical Analysis: The Rhysida Playbook

Rhysida operates as a ransomware-as-a-service (RaaS) operation and has been documented by CISA, the FBI, and HHS in joint advisories (AA23-319A) for campaigns against government, education, healthcare, and manufacturing targets. No CVE was disclosed in connection with this specific Berlin incident, so we will not speculate on one — but Rhysida's historically documented initial access and execution tradecraft gives defenders concrete behaviors to hunt.

Initial Access Vectors (Historically Observed)

• Compromised or phished credentials against externally facing services — VPN concentrators, RDP gateways, and remote access portals lacking MFA remain the group's bread and butter.
• Phishing-delivered payloads establishing initial footholds on endpoints.
• Valid account abuse for lateral movement once inside (MITRE ATT&CK T1078).

In-Network Tradecraft

• Living-off-the-land execution: PowerShell and WMI for discovery and staging (T1059.001, T1047).
• Rclone and similar sync tools for bulk exfiltration to attacker-controlled cloud storage (T1567.002) — the most likely mechanism behind a 6TB theft.
• Mass encryption with a Rhysida payload, typically deployed via PsExec or Group Policy abuse after domain dominance is achieved (T1486, T1480).
• Shadow copy deletion via vssadmin or wmic to kill recovery options (T1490).
• Persistence and lateral movement through RDP, SMB admin shares, and dumped credentials via tools in the Mimikatz family (T1003).

Exploitation Status

This is confirmed, active, in-the-wild criminal activity with completed data theft and public leak. It is not theoretical. Rhysida remains an active operation, and public-sector entities across Europe and North America should treat themselves as prospective targets.

Why 6TB of Exfiltration Should Have Been Caught

Bulk theft of that magnitude generates unavoidable telemetry: sustained high-volume egress to unusual destinations, archiving utilities (rar.exe, 7z.exe) running against file shares at odd hours, and sync-tool processes (rclone, MEGAcmd) that have no legitimate business purpose on government servers. If none of those fired an alert, the problem is not the adversary's sophistication — it is the absence of egress monitoring and exfiltration-focused detection content. That is fixable.

Detection & Response

The detections below target Rhysida's documented behaviors: shadow copy deletion, mass exfiltration tooling, and suspicious high-volume egress. They are tuned to minimize noise in a typical enterprise environment.

---
title: Shadow Copy Deletion via vssadmin or wmic
tid: 3f8c2a91-7b4e-4d1a-9c52-8e6f1a2b3c4d
status: experimental
description: Detects deletion of volume shadow copies, a hallmark ransomware pre-encryption behavior observed in Rhysida and peer operations.
references:
  - https://attack.mitre.org/techniques/T1490/
  - https://www.cisa.gov/news-events/cybersecurity-advisories/aa23-319a
author: Security Arsenal
date: 2026/04/06
tags:
  - attack.impact
  - attack.t1490
logsource:
  category: process_creation
  product: windows
detection:
  selection_img:
    Image|endswith:
      - '\vssadmin.exe'
      - '\wmic.exe'
      - '\bcdedit.exe'
      - '\wbadmin.exe'
  selection_cli:
    CommandLine|contains:
      - 'delete shadows'
      - 'shadowcopy delete'
      - 'delete catalog'
      - 'recoveryenabled no'
  condition: selection_img and selection_cli
falsepositives:
  - Legitimate backup maintenance by backup administrators; rare on servers and workstations outside maintenance windows
level: high
---
title: Rclone or Cloud Sync Tool Execution on Servers
tid: 8d1e5f42-3a6b-4c7d-b812-5f9a0c1d2e3f
status: experimental
description: Detects execution of rclone, MEGAcmd, or similar cloud synchronization tools commonly abused by ransomware groups including Rhysida for bulk data exfiltration.
references:
  - https://attack.mitre.org/techniques/T1567/002/
author: Security Arsenal
date: 2026/04/06
tags:
  - attack.exfiltration
  - attack.t1567.002
logsource:
  category: process_creation
  product: windows
detection:
  selection:
    Image|endswith:
      - '\rclone.exe'
      - '\megacmd.exe'
      - '\MEGAsync.exe'
      - '\filezilla.exe'
      - '\winscp.exe'
  filter_known_paths:
    Image|startswith:
      - 'C:\Program Files\BackupAgent\'
  condition: selection and not 1 of filter_known_paths*
falsepositives:
  - Legitimate file transfer utilities used by IT staff; whitelist by approved install path and service account
level: high
---
title: Mass Archive Creation Prior to Exfiltration
tid: 5b2c7d63-9e1f-4a8b-c345-2d7e8f9a0b1c
status: experimental
description: Detects archiving utilities invoked with compression flags against directories, consistent with ransomware staging of stolen data before exfiltration.
references:
  - https://attack.mitre.org/techniques/T1560/001/
author: Security Arsenal
date: 2026/04/06
tags:
  - attack.collection
  - attack.t1560.001
logsource:
  category: process_creation
  product: windows
detection:
  selection_img:
    Image|endswith:
      - '\rar.exe'
      - '\7z.exe'
      - '\7za.exe'
      - '\winzip.exe'
  selection_cli:
    CommandLine|contains:
      - ' a '
      - ' -r'
      - ' -p'
  selection_user:
    User|contains: 'SYSTEM'
  condition: selection_img and selection_cli and not selection_user
falsepositives:
  - Software packaging and admin archival tasks; correlate with user context and time of day
level: medium

// Hunt for high-volume outbound transfers to non-corporate destinations,
// consistent with ransomware double-extortion exfiltration staging.
// Tune the threshold and the known-destination list to your environment.
let KnownDestinations = dynamic(["sharepoint.com", "microsoftonline.com", "windows.net", "amazonaws.com"]);
let ThresholdBytes = 5000000000; // 5 GB per device per day
DeviceNetworkEvents
| where TimeGenerated > ago(7d)
| where ActionType == "ConnectionSuccess"
| where RemoteIPType == "Public"
| where not(RemoteUrl has_any (KnownDestinations))
| summarize TotalBytesSent = sum(tolong(BytesSent)), Connections = count(),
    Processes = make_set(InitiatingProcessFileName, 10),
    Destinations = make_set(RemoteUrl, 10)
    by DeviceName, bin(TimeGenerated, 1d)
| where TotalBytesSent > ThresholdBytes
| project TimeGenerated, DeviceName, TotalBytesSent, Connections, Processes, Destinations
| sort by TotalBytesSent desc;

// Companion hunt: shadow copy deletion and backup tampering across the estate
DeviceProcessEvents
| where TimeGenerated > ago(7d)
| where FileName in~ ("vssadmin.exe", "wmic.exe", "bcdedit.exe", "wbadmin.exe")
| where ProcessCommandLine has_any ("delete shadows", "shadowcopy delete", "delete catalog", "recoveryenabled no")
| project TimeGenerated, DeviceName, AccountName, FileName, ProcessCommandLine, InitiatingProcessFileName
| sort by TimeGenerated desc;

-- Hunt for exfiltration tooling and suspicious egress connections on endpoints
SELECT Pid, Name, CommandLine, Exe, Username, CreateTime
FROM pslist()
WHERE Name =~ '(?i)(rclone|megacmd|megasync|winscp|filezilla|7z|7za|rar)'
   OR CommandLine =~ '(?i)(delete shadows|shadowcopy delete|recoveryenabled no)'

-- Correlate with active outbound connections from unusual processes
SELECT Pid, Name, Family, Status, RemoteAddr, RemotePort
FROM netstat()
WHERE Status =~ 'ESTABLISHED'
  AND RemotePort in (21, 22, 443, 8443, 9001)
  AND Name =~ '(?i)(rclone|megacmd|powershell|wscript|rundll32)'

# Rhysida-style ransomware hardening and verification script
# Run elevated on servers and critical endpoints. Review before production use.

# 1. Verify VSS is protected and shadow copies exist (recovery baseline)
Write-Host "=== Shadow Copy Status ===" -ForegroundColor Cyan
vssadmin list shadows
Get-Service VSS | Select-Object Name, Status, StartType

# 2. Block common exfiltration tooling via AppLocker-style executable deny
# (Illustrative: enforce via WDAC/AppLocker policy in production)
$blockedTools = @("rclone.exe", "megacmd.exe", "megasync.exe")
foreach ($tool in $blockedTools) {
    $found = Get-ChildItem -Path "C:\" -Filter $tool -Recurse -ErrorAction SilentlyContinue -Depth 4
    if ($found) { Write-Host "[!] Found $tool at: $($found.FullName)" -ForegroundColor Red }
}

# 3. Audit for SMB admin share exposure and disable unused shares
Get-SmbShare | Where-Object { $_.Name -notin @("ADMIN$", "C$", "IPC$") } |
    Select-Object Name, Path, CurrentUsers

# 4. Enforce MFA on remote access: verify NPS/VPN policy presence
Write-Host "=== Remote Access Services ===" -ForegroundColor Cyan
Get-WindowsFeature | Where-Object { $_.Name -match "NPAS|RemoteAccess" -and $_.Installed }

# 5. Enable PowerShell Script Block Logging and Module Logging (detection telemetry)
$sbPath = "HKLM:\SOFTWARE\Policies\Microsoft\Windows\PowerShell\ScriptBlockLogging"
if (-not (Test-Path $sbPath)) { New-Item -Path $sbPath -Force | Out-Null }
Set-ItemProperty -Path $sbPath -Name "EnableScriptBlockLogging" -Value 1
Write-Host "[+] Script Block Logging enabled" -ForegroundColor Green

# 6. Enable detailed file share auditing for staging detection
auditpol /set /subcategory:"Detailed File Share" /success:enable /failure:enable
auditpol /set /subcategory:"File Share" /success:enable /failure:enable

# 7. Verify offline/immutable backup presence (the real ransom insurance)
Write-Host "=== Last Backup Check ===" -ForegroundColor Cyan
Get-WBBackupSet -ErrorAction SilentlyContinue | Select-Object BackupTime, BackupTarget

Remediation and Hardening Priorities

There is no patch for this incident class — there is posture. Prioritize the following:

1. Kill unauthenticated remote access. Enforce phishing-resistant MFA (FIDO2 where possible) on every VPN, RDP gateway, and remote management interface. Rhysida's access vector of choice is valid credentials against exposed services. Audit for stale service accounts with remote access rights.

2. Instrument egress before you need it. A 6TB theft is a months-long telemetry gift you failed to open. Deploy NetFlow or proxy-based egress monitoring with alerting on volume thresholds per host, plus DNS analytics to catch sync-tool callbacks. The KQL hunt above is a starting point; productionize it.

3. Block exfiltration tooling by policy. Rclone, MEGAcmd, and peer tools have no business case on most government and enterprise servers. Enforce WDAC or AppLocker policies that deny them outside an approved exception list, and alert on execution attempts.

4. Immutable, offline, tested backups. Ransom refusal only works as a strategy when restoration is viable. Maintain at least one backup copy that is offline or immutable (WORM/object-lock), segregated by credentials, and — critically — restoration-tested quarterly. Berlin's data is gone; availability of systems is the only variable you still control after a leak.

5. Segment to contain blast radius. Rhysida deploys encryption after achieving domain-wide reach. Tiered administration (per Microsoft's Enterprise Access Model), host-based firewalling between workstation VLANs and server segments, and disabling SMBv1/lateral RDP between workstations materially slows mass deployment.

6. Pre-plan the leak scenario. Your IR plan must answer, in writing, before the incident: Who decides on ransom posture? Who notifies data protection authorities (GDPR Article 33's 72-hour clock in the EU)? What is the communication plan when state or citizen data hits a leak site? Review CISA's #StopRansomware guidance for Rhysida (AA23-319A) and map your controls against it.

7. Threat hunt on dwell-time indicators now. Run the detections above retroactively over 30–90 days of telemetry. If Rhysida-style staging happened last quarter, you want to find it before the leak post, not after.

Berlin's refusal to pay was arguably the correct strategic decision — paying funds the next campaign and guarantees nothing about deletion. But it was a decision made inside a losing position. The organizations that come out of these incidents intact are the ones that made the breach expensive and loud long before the encryption ran.

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