Ripper Ransomware The Shift Toward PersonalizedCyber Extortion

Ripper is a newly discovered Windows-focused ransomware that encrypts victim files and implements a victim-centric extortion workflow.
It applies RSA and AES cryptographic techniques and renames encrypted files using the extension *.ripper12.
The actors change desktop wallpapers and drop a ransom note (READ_NOTE.html) to instruct victims on contact methods and ransom demands.

Technical Architecture & Cryptography

Like many modern ransomware families, Ripper likely uses a hybrid cryptographic model:
- AES (Advanced Encryption Standard) for the fast bulk encryption of files.
- RSA (Rivest-Shamir-Adleman) for encrypting the AES session keys so only the attacker’s private key can restore them.
This two-layer model is standard in robust ransomware because:
- AES is computationally efficient on large datasets.
- RSA protects the AES key with asymmetric encryption, making unauthorized decryption impractical without the corresponding RSA private key.
Similar patterns have been observed in classic crypto-ransomware designs such as Linux.Encoder and others that combine symmetric and public-key cryptography to secure both content and keys.

Below is a synthesis based on the CYFIRMA report and standard ransomware behavior:

Initial Access:
- Entry likely achieved through phishing, remote access compromise, or removable media replication (T1091).
Execution & Persistence:
- Execution through scripting interpreters (e.g., PowerShell), scheduled tasks, registry run keys (T1059, T1547.001).
- Modifies registry and boot sequences to ensure persistence even after reboots.
Defense Evasion:
- Use of code obfuscation or packing to hide malicious logic from static analysis and evade detection.
- Deletes system restore points via commands like vssadmin delete shadows /all /quiet to prevent rollback recovery.
Privilege Escalation:
- Process injection and token manipulation to elevate privileges and bypass security controls.
Discovery & Lateral Movement:
- Enumeration of files and devices before encryption, and possible spread through shared media.
Impact:
- Encrypts data (T1486), destroys backups (T1490), and may exfiltrate sensitive data for extortion leverage.

Ripper’s hybrid cryptographic workflow resembles how other families pair symmetric and asymmetric keys to protect contents and decryption keys — a widely documented approach in modern ransomware analysis.
The addition of victim profiling and negotiation workflow (supplying decrypted samples, time-based price increase, Tor/email contact) aligns with organized ransomware operations — often seen in double-extortion campaigns.

Renaming of files with a consistent extension (.ripper12) serves as a clear marker of compromise.

Presence of malicious scheduled tasks set to SYSTEM privileges with recurring triggers.
Registry run key modifications to auto-launch ransomware or cleanup scripts.

Ransom notes threatening data exposure are part of modern extortion tactics, paralleling leakware/doxware — ransomware that couples encryption with threats to publish stolen data.

Tools should monitor:
- Unusual creation/modification of scheduled tasks.
- Process injection events and suspicious registry edits.
- Mass file write/encryption patterns at unusual speed (detectable via kernel-level event traces or behavioral EDR heuristics).

Restrict outbound traffic to unknown addresses to limit command-and-control (C2) communication — often using encrypted channels post-compromise.

Maintain air-gapped backups and test recovery capabilities frequently to mitigate encryption impact, as traditional ransomware forecloses shadow copies and restore points.

Operational maturity: The tailored negotiation processes suggest evolving sophistication beyond opportunistic malware, hinting at potential expansion into broader Ransomware as a Service (RaaS) domains.
As seen with established ransomware like Akira or BQT.Lock, successful variants often follow with affiliate programs, improved evasion, and expanded cryptographic models.