Suspicious PowerShell ReadAllBytes and Expand-Archive Payload Staging (via process_creation)

ATT&CK techniques

Execution

Recon
Resource Dev
Initial Access
Execution
- T1059.001PowerShell
- T1204.002Malicious File
Persistence
Priv Esc
Defense Evasion
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact

What it detects

This rule detects PowerShell reading raw bytes from a dropped file and expanding an archive in the same command, a loader chain launched from a malicious LNK in the SmugX campaign delivering PlugX. Chaining ReadAllBytes with Expand-Archive is characteristic of staged payload extraction rather than normal scripting.

Reporting behind it

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Suspicious PowerShell ReadAllBytes and Expand-Archive Payload Staging (via process_creation)

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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