Validate Insider-Threat Tip and Choose Investigation Posture
Before any data collection, validate the tip's credibility and choose the investigation posture: covert (silent monitoring, preserve evidence without tipping the subject) or overt (immediate access restriction, subject interview). The posture choice determines every subsequent technical step and cannot easily be reversed.
Actions
- 1
Review the source of the tip: HR complaint, manager concern, colleague report, automated UEBA alert, vendor escalation. Record the source and any reliability signals.
- 2
Cross-check the tip against accessible baseline signals without pulling user-specific data: aggregate UEBA risk score, DLP alert counts, access-review flags, prior HR case history (with privacy controls).
- 3
Meet with HR, legal, and security management together -- never solo -- to decide posture (covert vs overt). The meeting itself should be documented with minimal detail and restricted access.
- 4
If covert: design the evidence-collection plan to avoid notifications (no forced password resets, no EDR-quarantine actions, no conditional-access changes) that would alert the subject.
- 5
If overt: plan the immediate-response sequence (access restriction, device collection, interview) with legal/HR on the bridge.
Queries
Does the user's UEBA risk score fall outside their 90-day baseline, and what specific signals drive the score?
Has the user triggered DLP policies in the last 90 days, and at what severity?
Notes
Posture mistakes are often irreversible: once the subject is tipped, covert evidence collection is no longer possible. Slow down the first hours rather than rush.
HR and legal participation is mandatory, not optional. Security-led insider investigations without HR/legal expose the organization to wrongful-termination, privacy, and evidence-admissibility risks.
If the tip source is a colleague, carefully assess retaliation risk and ensure the source is protected in any onward communication.