# Centro Médico Especializado OSI ransomware attack

Published: 2026-08-23 · Severity: routine · Sectors: healthcare
Canonical: https://vorant.io/reports/a0447015-599f-5a12-aac6-c2cb65e8efdd/centro-m-dico-especializado-osi-ransomware-attack

> Healthcare provider Centro Médico Especializado OSI compromised with 222 user credentials exposed.

Centro Médico Especializado OSI, a healthcare solutions provider, has been identified as a ransomware victim. The breach resulted in the compromise of 222 user credentials and one third-party employee credential. The organization's external attack surface included 13 exposed DNS records. This incident appears to be indexed by ransomware.live as part of public reporting on ransomware operations. The compromise represents a data exposure event affecting healthcare infrastructure and employee access credentials.

## Mentioned in this report

- Malware: Kazu

## Detection guidance (public sample)

### Packet Capture or Network Sniffing Tool Execution on Windows

ATT&CK: T1040

Detects execution of packet-capture utilities (tshark, dumpcap, WinDump) or built-in capture via netsh trace and pktmon, which attackers use to sniff credentials on the network. Auto-generated starting point — validate and tune in your environment before deploying. IOC matches can false-positive on shared infrastructure and decay as adversary infrastructure rotates.

```yaml
title: Packet Capture or Network Sniffing Tool Execution on Windows
description: Detects execution of packet-capture utilities (tshark, dumpcap, WinDump)
  or built-in Windows capture features (netsh trace start, pktmon start) that adversaries
  use to sniff credentials from network traffic. Context is needed, as admins and
  network engineers also use these tools.
tags:
- attack.credential-access
- attack.discovery
- attack.t1040
logsource:
  category: process_creation
  product: windows
detection:
  selection_tools:
    Image|endswith:
    - \tshark.exe
    - \dumpcap.exe
    - \windump.exe
  selection_netsh:
    Image|endswith: \netsh.exe
    CommandLine|contains|all:
    - trace
    - start
  selection_pktmon:
    Image|endswith: \pktmon.exe
    CommandLine|contains: start
  condition: 1 of selection_*
falsepositives:
- Network or helpdesk engineers capturing traffic to troubleshoot connectivity
- Security teams running Wireshark/dumpcap for authorised analysis
level: medium
id: d9182904-6d12-501c-87f6-f0dd0107b845
status: experimental
author: Vorant
references:
- https://www.ransomware.live/id/Q2VudHJvIE3DqWRpY28gRXNwZWNpYWxpemFkbyBPU0k6IEhlYWx0aGNhcmUgU29sdXRpb25zQGthenU=
```

### Network Brute-Force Tool Execution on Linux

ATT&CK: T1110

Detects execution of well-known online password brute-forcing tools (hydra, medusa, ncrack) on Linux hosts. Auto-generated starting point — validate and tune in your environment before deploying. IOC matches can false-positive on shared infrastructure and decay as adversary infrastructure rotates.

```yaml
title: Network Brute-Force Tool Execution on Linux
description: Detects execution of online password-guessing tools such as hydra, medusa
  and ncrack on Linux hosts, consistent with brute-force or credential-stuffing against
  exposed services.
tags:
- attack.credential-access
- attack.t1110
logsource:
  category: process_creation
  product: linux
detection:
  selection:
    Image|endswith:
    - /hydra
    - /medusa
    - /ncrack
  condition: selection
falsepositives:
- Authorised penetration tests or red-team exercises
- Security staff auditing password strength on internal systems
level: high
id: 8d694bc0-2a59-535e-81fe-0a8b3dbf2d2d
status: experimental
author: Vorant
references:
- https://www.ransomware.live/id/Q2VudHJvIE3DqWRpY28gRXNwZWNpYWxpemFkbyBPU0k6IEhlYWx0aGNhcmUgU29sdXRpb25zQGthenU=
```

Behavioural rules are generated from public reporting — validate in your environment before deploying.

1 more detection for this report is in the app: the rules that match its indicators, the Sigma rules already converted to Splunk SPL, to Elastic where their fields map onto Elastic's integrations and to Microsoft Defender XDR KQL wherever Defender records the activity, and the YARA and Suricata. A new account gets three days of them free.

Source reporting: https://www.ransomware.live/id/Q2VudHJvIE3DqWRpY28gRXNwZWNpYWxpemFkbyBPU0k6IEhlYWx0aGNhcmUgU29sdXRpb25zQGthenU=

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