ctblocker

Also known as: ctblocker

aka Critroni
CTB‑Locker emerged in mid‑2014, introducing a new era of ransomware by leveraging elliptic curve cryptography (ECC), Tor-based C&C communication, and Bitcoin payments—earning its name from “Curve-Tor-Bitcoin Locker.” It was packaged and sold as a ransomware kit for approximately $1,500–$3,000, allowing affiliates to deploy customized campaigns. The malware encrypts user data (including network and removable drives), changes desktop wallpapers, and appends file extensions like .CTBL, .CTB2, or randomized strings. Victims receive instructions for payment, typically within a limited timeframe, or risk permanent data loss. In 2015–2017, law enforcement and cybersecurity firms (including McAfee and Kaspersky) disrupted the network, arrested operators, and facilitated decryption tools.

Introduction

aka Critroni
CTB‑Locker emerged in mid‑2014, introducing a new era of ransomware by leveraging elliptic curve cryptography (ECC), Tor-based C&C communication, and Bitcoin payments—earning its name from “Curve-Tor-Bitcoin Locker.” It was packaged and sold as a ransomware kit for approximately $1,500–$3,000, allowing affiliates to deploy customized campaigns. The malware encrypts user data (including network and removable drives), changes desktop wallpapers, and appends file extensions like .CTBL, .CTB2, or randomized strings. Victims receive instructions for payment, typically within a limited timeframe, or risk permanent data loss. In 2015–2017, law enforcement and cybersecurity firms (including McAfee and Kaspersky) disrupted the network, arrested operators, and facilitated decryption tools.

Activities and Tactics

Information pending cataloguing.

Notable Campaigns

Information pending cataloguing.

Tactics, Techniques, and Procedures (TTPs)

Information pending cataloguing.

Notable Indicators of Compromise (IOCs)

No curated IOCs are currently published for this actor. This section will be updated when stable, attributable indicators are available.

Malware and Tools

  • CyberGate:
  • Cyber Eye RAT:
  • DesktopNow:
  • GraphicBooting:

Attribution and Evidence

Information pending cataloguing.

References

References pending cataloguing.