This hypothesis targets the presence of WannaCryptor ransomware by correlating known IOCs with indicators of rapid file encryption and lateral movement, which are critical signs of active ransomware deployment. Proactively hunting for these patterns in Azure Sentinel allows the SOC to identify and isolate compromised endpoints before the encryption process completes, thereby minimizing data loss and operational downtime.
Malware Family: WannaCryptor Total IOCs: 3 IOC Types: sha256_hash, sha1_hash, md5_hash
| Type | Value | Threat Type | First Seen | Confidence |
|---|---|---|---|---|
| md5_hash | f5ec29d01c9adb0ecabb2da6bc8fb81a | payload | 2026-09-24 | 95% |
| sha256_hash | 541677c2ce44edbb6241907c36463e6ded77a9d7cdb48ceb4113f1111ad2f9e8 | payload | 2026-09-24 | 95% |
| sha1_hash | aafeaf4892cd200b9dd7b9e03259b49204d2973b | payload | 2026-09-24 | 95% |
// Hunt for files matching known malicious hashes
// Source: ThreatFox - WannaCryptor
let malicious_hashes = dynamic(["f5ec29d01c9adb0ecabb2da6bc8fb81a", "541677c2ce44edbb6241907c36463e6ded77a9d7cdb48ceb4113f1111ad2f9e8", "aafeaf4892cd200b9dd7b9e03259b49204d2973b"]);
DeviceFileEvents
| where SHA256 in (malicious_hashes) or SHA1 in (malicious_hashes) or MD5 in (malicious_hashes)
| project Timestamp, DeviceName, FileName, FolderPath, SHA256, InitiatingProcessFileName
| order by Timestamp desc| Sentinel Table | Notes |
|---|---|
DeviceFileEvents | Ensure this data connector is enabled |
Scenario: An IT administrator runs a scheduled PowerShell script using Get-ChildItem and Compress-Archive to back up user profile folders to a network share before applying Windows Updates. The rapid creation of temporary encrypted/compressed files and high network throughput to the backup server mimics the “rapid file encryption” and “unusual network traffic” patterns described in the rule.
powershell.exe or pwsh.exe and the command line contains specific backup keywords (e.g., Compress-Archive, robocopy, backup) or where the destination path matches known backup share UNC paths (e.g., \\fileserver\backups\).Scenario: A DevOps team executes a CI/CD pipeline job that uses openssl enc or 7z to encrypt source code artifacts or logs before pushing them to a secure artifact repository (e.g., JFrog Artifactory or Nexus). This legitimate encryption activity generates high CPU usage and temporary file modifications that align with the “file encryption” IOC.
openssl.exe, 7z.exe, or tar.exe and the working directory or command line references standard CI/CD tooling paths (e.g., .git, node_modules, build/, artifacts/) or known CI/CD service accounts (e.g., svc-ci, jenkins).Scenario: A security engineer performs a manual penetration test or vulnerability scan using tools like Nmap or Masscan against internal subnets. The resulting burst of SYN/ACK packets and connection attempts to multiple hosts can trigger “lateral movement” or “unusual network traffic” alerts, especially if the scanner is run from a jump host with broad permissions.