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Krybit leaks ProHealth Singapore VPN creds

high threat healthcare

Ransomware group Krybit exposed FortiOS SSL-VPN credentials for Singapore's ProHealth, tied to the 2022 FortiBleed flaw (CVE-2022-40684).

Ransomware.live has indexed a leak entry attributed to the Krybit ransomware operation, listing prohealth.sg (ProHealth Singapore) as a victim. The listing states that the organization's FortiOS SSL-VPN credentials were exposed via the FortiBleed vulnerability, an authentication bypass in Fortinet's FortiOS/FortiProxy administrative interface that was disclosed in 2022 and has been widely abused by multiple threat actors to harvest VPN credentials and gain initial network access.

The entry appears to be a standard victim-shaming leak post rather than a detailed technical disclosure, providing DNS records and a screenshot as proof of compromise. No malware samples, additional infrastructure, or a full description of the intrusion chain following credential theft were provided in the source material. Given the healthcare sector nexus and use of a known, patchable Fortinet vulnerability for initial access, this represents a routine but concerning case of unpatched edge infrastructure being leveraged for ransomware operations.

Mentioned in this report

Vulnerabilities CVE-2022-40684KEV
Threat actors Krybit

Detection guidance

FortiOS SSL-VPN Authentication Bypass Exploitation Attempts

ATT&CK T1190

Detects HTTP requests to FortiOS administrative interface paths known to be vulnerable to authentication bypass (FortiBleed CVE-2022-40684), typically targeting /api/v2/cmdb or /api/v2/monitor endpoints without proper authentication headers. 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.

title: FortiOS SSL-VPN Authentication Bypass Exploitation Attempts
description: Detects HTTP requests to FortiOS administrative API endpoints vulnerable
  to FortiBleed authentication bypass. Targets /api/v2/cmdb and /api/v2/monitor paths
  accessed without valid session tokens, consistent with exploitation attempts to
  harvest credentials.
tags:
- attack.initial-access
- attack.t1190
logsource:
  category: proxy
  product: fortinet
detection:
  selection_vulnerable_paths:
    http_request_line|contains:
    - /api/v2/cmdb
    - /api/v2/monitor
    http_method:
    - GET
    - POST
  filter_legitimate_admin:
    source_ip|startswith:
    - '10.'
    - 172.16.
    - 192.168.
  condition: selection_vulnerable_paths and not filter_legitimate_admin
falsepositives:
- Legitimate FortiOS administrative access from internal networks
- Authorized vulnerability scanning of Fortinet appliances
level: high
id: 06815aea-e116-53e1-9229-7b58bf0bf6fb
status: experimental
author: Vorant

Suspicious VPN Credential Access from FortiOS Administrative Interface

ATT&CK T1078

Detects FortiOS administrative API queries targeting user credential endpoints (/api/v2/cmdb/user or /api/v2/cmdb/vpn) that typically precede credential harvest operations. 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.

title: Suspicious VPN Credential Access from FortiOS Administrative Interface
description: Detects HTTP requests to FortiOS API endpoints exposing VPN user credentials
  and authentication objects. Targets /api/v2/cmdb/user and /api/v2/cmdb/vpn paths
  accessed via unauthenticated or low-privilege sessions, consistent with credential
  enumeration following FortiBleed exploitation.
tags:
- attack.credential-access
- attack.t1078
logsource:
  category: proxy
  product: fortinet
detection:
  selection_credential_endpoints:
    http_request_line|contains:
    - /api/v2/cmdb/user
    - /api/v2/cmdb/vpn
    - /api/v2/cmdb/authentication
    http_method:
    - GET
    - POST
  selection_suspicious_access:
    http_status_code: 200
    source_ip|contains:
    - ':'
  filter_internal_admin:
    source_ip|startswith:
    - '10.'
    - 172.16.
    - 192.168.
  condition: selection_credential_endpoints and selection_suspicious_access and not
    filter_internal_admin
falsepositives:
- Legitimate FortiOS backup and configuration export operations by administrators
- Authorized API clients querying user objects for management purposes
level: medium
id: 4a3df361-36d7-5f09-9cba-65b6d052b9c6
status: experimental
author: Vorant

FortiOS Administrative Interface Accessed Without Valid Session

ATT&CK T1190

Detects HTTP requests to FortiOS administrative web interface (/admin or /dashboard paths) returning HTTP 200 without corresponding authenticated session tokens, indicating potential authentication bypass. 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.

title: FortiOS Administrative Interface Accessed Without Valid Session
description: Detects successful HTTP requests to FortiOS administrative interface
  paths without valid session authentication, typical of FortiBleed CVE-2022-40684
  exploitation where attackers bypass authentication checks on the admin backend.
tags:
- attack.initial-access
- attack.t1190
logsource:
  category: proxy
  product: fortinet
detection:
  selection_admin_paths:
    http_request_line|contains:
    - /admin
    - /dashboard
    - /ng
    destination_port: 443
  selection_no_auth:
    http_status_code: 200
    http_request_headers|contains:
    - Cookie
  filter_valid_session:
    http_request_headers|contains:
    - PHPSESSID
    - ccsrftoken
  condition: selection_admin_paths and selection_no_auth and not filter_valid_session
falsepositives:
- Legitimate administrative access with session tokens in request body instead of
  headers
- Network monitoring tools querying appliance status endpoints
level: high
id: b09a66aa-70a4-511c-8fd8-8d706eb7b5a3
status: experimental
author: Vorant

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

Source reporting: https://www.ransomware.live/id/d3d3LnByb2hlYWx0aC5zZ0BrcnliaXQ=

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