Ryuk | Threat Level: critical | Type: Ransomware

Cryptographic Identifiers

SHA25688b1b4966650de59cef20c340b28739c52dc9ead91d9959a338a8e531ad38335
MD56cad2f7dc809b9353a31753a438aef4e
File Typeexe
Size575.5 KB
First Seen2021-01-18
File Name88b1b4966650de59cef20c340b28739c52dc9ead91d9959a338a8e531ad38335
TagsRansomware, Ryuk

Malware Family: Ryuk

Ryuk, hastane hedefler.

TypeRansomware
Programming LanguageC
Target PlatformWindows
C2 Protocol
PurposeHastane ransomware
First Seen Year2018

Threat Indicators (IOC)

  • SHA256: 88b1b4966650de59cef20c340b28739c52dc9ead91d9959a338a8e531ad38335
  • MD5: 6cad2f7dc809b9353a31753a438aef4e

You can verify all hash values of this sample on VirusTotal.

System Cleanup Guide

  1. Sistemi ağdan DERHAL ayırın — diğer cihazlara yayılmayı durdurun
  2. Do not pay the ransom — there is no guarantee your files will be restored
  3. Quarantine the affected drives
  4. Kullanılan fidye yazılımı ailesini belirleyin (nomoreransom.org)
  5. Try available decryptor tools (the NoMoreRansom project)
  6. Report the incident to the authorities (cybercrime unit)
  7. Temiz bir yedekten kurtarın; yedeğiniz yoksa sürücüyü saklayın

YARA Rule Hints

rule Ryuk_SHA256 {
    meta:
        description = "Ryuk sample: 88b1b4966650de59"
        threat_level = "critical"
        first_seen = "2021-01-18"
    condition:
        hash.sha256(0, filesize) == "88b1b4966650de59cef20c340b28739c52dc9ead91d9959a338a8e531ad38335"
}

Ryuk — Malware Profile

Wizard Spider threat group ransomware (2018+). Targets large enterprises, hospitals, municipalities. RyukReadMe.html ransom note. VirtualAllocEx+WriteProcessMemory+CreateRemoteThread injection. GetIpNetTable ARP scan for lateral movement. AdjustTokenPrivileges for SeBackupPrivilege/SeDebugPrivilege.

Malware Type
Ransomware
Programming Language
C
C2 Protocol
Target Systems
Windows

Technical Details

Ryuk ransomware emerged August 2018, operated by WIZARD SPIDER (TrickBot operators). Targeted large organizations for high ransoms ($100K-$12.5M+ per victim). Distribution: delivered via TrickBot/BazarLoader infections (human-operated). Encryption: RSA-2048 + AES-256 (CBC mode), unique key per file. Stops 40+ Windows services (backup, antivirus, database) and kills >180 processes. Deletes volume shadow copies (vssadmin delete shadows /all /Quiet). Disables Windows recovery: bcdedit /set {default} recoveryenabled No. Network propagation: uses Wake-on-LAN to activate sleeping network hosts for encryption. Believed based on Hermes ransomware sold by a North Korean-linked actor on underground forums. Predecessor to Conti ransomware which emerged from WIZARD SPIDER's operations in 2020.

Attribution / Threat Actor

WIZARD SPIDER (linked to Hermes/Lazarus initial code)

Capabilities & Behavior

Dosya Şifreleme (AES/RSA)
Gölge Kopya Silme
Yedek Kaldırma
Fidye Notu Oluşturma
Kalıcılık Sağlama
Ağ Paylaşımı Şifreleme
Anti-Analiz Teknikleri
Çift Gasp (Data Leak)

IOC List (2 indicators)

IOC — Ryuk
# SHA256 88b1b4966650de59cef20c340b28739c52dc9ead91d9959a338a8e531ad38335 # MD5 6cad2f7dc809b9353a31753a438aef4e
TypeValueNote
sha256 88b1b4966650de59cef20c340b28739c52dc9ead91d9959a338a8e531ad38335 Sample:Ryuk
md5 6cad2f7dc809b9353a31753a438aef4e Sample:Ryuk

C2 Servers (2 recorded servers for this family)

Address Type Port Protocol Status Country
51.161.204.106 ip 443 HTTPS sinkholed CA
162.119.249.198 ip 443 HTTPS sinkholed US

C2 addresses are provided only from malware samples manually verified by the KEYDAL team. Commercial use is prohibited.

Tags
ryukransomwaremalwarecriticalsha256hash-analizi