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Malware

Backdoor

Backdoor

A hidden access path that lets an attacker return without normal authentication.

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MIGHT YOU BE AFFECTED?

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How does this work?

It bypasses usual controls and provides lasting secret access, often after a vulnerability is exploited or a Trojan installed.

REAL-WORLD EXAMPLE

« A hidden service listens on an unusual port and enables access even after passwords change. »

Typical sequence

  1. 1Gain initial access
  2. 2Install hidden access
  3. 3Return later

Warning signs

  • Unknown account or service
  • Unexpected network port
  • Persistent outbound connection

How to protect yourself

  • Use endpoint detection and inventory services
  • Segment networks and minimise privileges
  • Patch vulnerabilities promptly

If you think you are affected

Isolate the system and investigate the initial intrusion before removing the backdoor. Revoke sessions, keys and secrets that may have been compromised.

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Last updated: 6 September 2026