Malicious Regsvr32 Executing DLL From Windows Temp

ATT&CK techniques

Defense Evasion

Recon
Resource Dev
Initial Access
Execution
Persistence
Priv Esc
Defense Evasion
- T1218.010Regsvr32
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact

What it detects

This rule detects regsvr32.exe registering or executing a DLL located in the Windows Temp directory which the ALPHV intrusion used after a VBS dropper wrote a payload there and this matters because regsvr32 loading a DLL from Temp is a common proxy execution and squiblydoo style evasion pattern that legitimate software does not exhibit.

Reporting behind it

Related detections9 linkedT1218.010 — drag to rearrange

Suspicious Regsvr32 Execution of SafePay Loader DLL

Suspicious Scheduled Task Running Regsvr32 with Extreme Duration by StaryDobry

Malicious DynamicWrapperX Registration via regsvr32 (via process_creation)

Suspicious Run Key Persistence Executing regsvr32

Suspicious regsvr32 Registering DLL from User AppData

Malicious Regsvr32 Loading Masqueraded VPN DLL via Process Creation

Malicious Regsvr32 ShellExec_RunDLL Proxy Execution (via process_creation)

Suspicious DLL Execution via Regsvr32 DllInstall of dat File

Malicious Xctdoor XcLoader Execution via Regsvr32 AppX Path Abuse (via process_creation)

Malicious Regsvr32 Executing DLL From Windows Temp

Pivot detection · T1218.010 · 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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