ELI5: What is Locker Ransomware?

Instead of scrambling your files, this type just locks your whole screen with a big scary message. Your stuff is usually still there — you just can’t get to it until you get past the lock.

Definition

Locker ransomware prevents users from accessing their systems by locking the desktop, displaying a full-screen ransom message, and disabling normal user interaction—without necessarily encrypting files. Unlike encryption-based ransomware, locker ransomware typically targets the operating system interface rather than individual files, making it somewhat less severe since files often remain intact on disk.

Key Details

  • Often targets the Windows login process or desktop shell to prevent normal OS operation.
  • May masquerade as law enforcement messages (“Your computer has been locked by the FBI”) to intimidate victims.
  • Early ransomware families (e.g., Police Trojan, Reveton) were primarily lockers.
  • Less destructive than encryption ransomware—files are not encrypted, so system restore or boot from external media may allow recovery.
  • Modern ransomware is predominantly encryption-based; locker ransomware is now less common but still encountered.

Connections