Sunday, May 10, 2020

Repost - ​Mossack Fonseca - Insider Threat - What would you do?

So with all the press related to the Panama Papers I began thinking again about insider threat. So here is a quick list of suggested actions specifically to tackle data leakage/whistleblowing/insider threat. This is a particularly difficult challenge in information security as you often need to provide access to all customer records to the lowest level of employees within the organisation to facilitate timely customer service processes.
  1. Engage an organisation to provide an independent whistleblower call center and encrypted contact form service with investigation support for the organisation to provide employees with an alternative to going to the press in case of middle and even senior management misconduct. This is a fail safe measure to prevent corporate data sets being exfiltrated to the press by well meaning if misguided employees. This also provides an increased ability for prosecution of insider malicious actors who may claim whistleblower protections as legal cover for a failed data theft/sale.
  2. Identify the most sensitive information in the organisation and the systems in which it resides. Check that access to this information is authenticated and logged ie. access to the content not just authentication success/failure.
  3. Investigate to see if there is an easily identifiable identifier for each customer record. Investigate its construction. Even consider modifying its construction so it is based on an algorithm that can easily be checked in a Data Leakage Prevention system signature to minimise false positives.
  4. Block unapproved file sharing, webmail and uncategorised websites in the corporate web proxy policy.
  5. Provide an approved file transfer capability for ad-hoc file sharingwith business partners
  6. Block USB storage device usage. Perhaps only allow the use of corporate issued encrypted USBs for the required edge use cases which enforce centralised logging of file activity.
  7. Implement TLS inspection of web traffic and Data Leakage Prevention (DLP) on endpoint, web and email traffic including coverage of the approved file transfer capability (while you are at it ensure opportunistic TLS support in email gateways is enabled for data in transit email protection with your business partners)
  8. Block the use of encrypted file attachments in outbound email in favour of the approved file transfer capability
  9. Implement a network surveillance system with TLS inspection, alert, traffic replay and alert suppression whitelisting capabilities
  10. Integrate DLP and network surveillance integrated into a workflowed case management system supported by a well resourced internal investigation and incident response function
  11. Insert honeytoken records into each of the sensitive customer data repositories so that when they are accessed across a network, the network surveillance generates alerts for mandatory investigation.
  12. Tune out the false positives from honeytoken alerts from regular batch file transfers between systems
  13. Revisit all of the customer data repositories and ensure that only a subset of users are authorised to access file export capabilities
  14. For key systems implement a privileged access management solution with surveillance of administrative access and workflowed tight integration with change and incident management approval for facilitation of timeboxed privileged access
Hope that gives you an insight into the complexities of tackling data leakage and insider threat. There are another two levels of detail under this plan required to execute this successfully through requirements, procurement, design build and run.
As always I am welcome to queries from fellow security professionals and interested executives.

1 comment:

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