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Persistence

Persistence is the set of techniques attackers use to maintain access to a compromised system over time, surviving reboots and remediation attempts.

What is persistence?How it typically works?Common techniques & variantsImpactFurther reading

What is persistence?

Persistence refers to methods used by an adversary to ensure continued access to a system after initial compromise. Rather than a single action it is a class of tactics and configurations that guarantee the attacker can return even after user logouts or system restarts. Persistence is critical to long running operations such as espionage, data theft, or staged ransomware deployment. Techniques range from modifying startup settings to installing services or abusing legitimate remote management features. Effective persistence may hide inside legitimate processes making detection by standard tools difficult.

How it typically works?

  1. Establish foothold: after initial access the attacker deploys mechanisms to survive system state changes.
  2. Implement persistence: modify system startup, install services, add scheduled tasks, or abuse system components.
  3. Validate: attacker confirms persistence survives reboots and updates.
  4. Maintain stealth: persistence is obfuscated to evade detection and resist removal.
  5. Rotate and fallback: attackers sometimes deploy multiple persistence methods to ensure one remains if others are removed.

Common techniques & variants

  • Startup and service modification: register programs to run at boot via services or startup folders.
  • Scheduled tasks abuse: create tasks that execute payloads on timers or triggers.
  • Credential and token persistence: steal or store tokens and credentials to reauthenticate later.
  • Firmware persistence: implant code in device firmware to survive disk reimage.
  • Legitimate feature abuse: exploit remote management or update frameworks to execute code under normal system privileges.

Impact

Persistence prolongs attacker presence and increases the cost and complexity of incident response. For SecOps teams persistence means that simple remediation such as removing a file or rebooting a host can be insufficient. Detecting persistence requires telemetry across system startup events, process behavior, and configuration drift. Removal often needs a coordinated approach including credential resets, reimaging where necessary, and verification that backdoors are not present in firmware or network appliances.

Further reading

  • MITRE ATT&CK: Persistence techniques matrix. Read more
  • CISA: Guidance on persistence indicators. Read more
  • Microsoft Security: Persistence mechanisms and defensive practices. Read more
  • SANS Institute: incident response case studies. Read more

Related topics

Lateral MovementExploit KitZero Day Exploits