Cactus Ransomware: Signs, removal steps, and prevention tips

Cactus Ransomware

What it is (in plain words):

Cactus sneaks into company networks through weak or outdated VPN setups, then locks (encrypts) files and demands money to unlock them. It’s a break-in via remote access, followed by a warehouse of locked boxes.

How it gets in:

  • Vulnerable or misconfigured VPNs/remote access

  • Stolen or weak admin passwords

  • Unpatched servers and apps

What you might notice:

  • Files won’t open; new extensions appear

  • Ransom notes in many folders

  • Security tools disabled; servers slow or unresponsive

If it hits, do this now:

  1. Isolate affected machines from the network

  2. Keep ransom notes/logs (don’t wipe evidence)

  3. Check offline backups and plan clean rebuilds

  4. Rotate admin/domain passwords from a clean device

  5. Contact IT/IR support; consider reporting to authorities

How to prevent it:

  • Patch VPNs, firewalls, and servers quickly

  • Enforce MFA on all remote access; limit admin rights

  • Use reputable EDR/anti-malware and email filtering

  • Keep offline, tested backups; run restore drills

  • Close unused remote-access paths

Learn more:
Cactus — behaviors, IOCs, and removal


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