Suspicious PowerShell Download Cradle via Net.WebClient DownloadFile

ATT&CK techniques

Execution → C2

Recon
Resource Dev
Initial Access
Execution
- T1059.001PowerShell
Persistence
Priv Esc
Defense Evasion
Cred Access
Discovery
Lateral Movement
Collection
C2
- T1105Ingress Tool Transfer
Exfiltration
Impact

What it detects

This rule detects PowerShell invoking the Net.WebClient DownloadFile method, a download cradle used by KoiLoader shortcut droppers to retrieve secondary payloads. Scripted retrieval of remote files through the .NET web client is a common ingress technique for loaders and should be reviewed in context.

Reporting behind it

Related detections9 linkedT1059.001 — drag to rearrange

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Suspicious PowerShell Remote Script Execution via IEX DownloadString

Suspicious PowerShell Download Cradle to Blogspot (via process_creation)

Suspicious Hidden PowerShell WebClient DownloadFile Cradle

Suspicious PowerShell Download Cradle with Spoofed User-Agent via MSIX

Malicious PowerShell In-Memory Download Cradle via Script Block (via ps_script)

Suspicious PowerShell Download Cradle via Net.WebClient DownloadFile

Pivot detection · T1059.001 · 9 related

Detection content is published as a reviewed draft. Tune thresholds and exclusions against your own telemetry before enabling this rule for alerting.

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