Severity
High
Analysis Summary
Ryuk is the name of a ransomware family, first discovered in the wild in August 2018. It is one of the nastiest ransomware going around. Ryuk will lock your files or systems and holds them hostage for ransom. Ryuk is a type of ransomware used in targeted attacks, where the threat actors make sure that essential files are encrypted so they can ask for large ransom amounts. A typical Ryuk ransom demand can amount to a few hundred thousand dollars. Ryuk is one of the first ransomware families to include the ability to identify and encrypt network drives and resources, as well as delete shadow copies on the endpoint. This means the attackers can then disable Windows System Restore for users, making it impossible to recover from an attack without external backups. Ryuk’s delivery method is spam emails. These emails are often sent from a spoofed address, so the sender’s name does not raise suspicion.
Impact
- File encryption
- Privilege Escalation
- Information Theft
- Data Exfiltration
- Network Compromise
Indicators of Compromise
MD5
- c0d6a263181a04e9039df3372afb8016
SHA-256
- 0b1008d91459937c9d103a900d8e134461db27c602a6db5e082ab9139670ccb6
SHA-1
- 50bf85255e28e42548d46b60f085c17f3675a208
Remediation
- Block all threat indicators at your respective controls.
- Search for IOCs in your environment.