Suspicious File Written to Startup Folder by DllHost COM Surrogate

ATT&CK techniques

Persistence → Priv Esc

Recon
Resource Dev
Initial Access
Execution
Persistence
- T1547.001Registry Run Keys / Startup Folder
Priv Esc
- T1547.001Registry Run Keys / Startup Folder
Defense Evasion
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact

What it detects

This rule detects dllhost.exe writing files into the user Startup folder, matching Blister loader behaviour that abuses the IFileOperation COM interface via the DllHost surrogate to copy its payload for persistence while evading direct file-write monitoring. The COM surrogate is rarely a legitimate producer of Startup persistence artifacts and indicates staging of an auto-run payload.

Reporting behind it

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Suspicious File Written to Startup Folder by DllHost COM Surrogate

Pivot detection · T1547.001 · 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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