High RiskWindowsLegitimateCommonly Abused
smartscreen.exeSECURITY FEATUREsmartscreen.exe - Windows SmartScreen Security Analysis
smartscreen.exe is the **Windows SmartScreen Filter** that protects against malicious downloads and websites. Attackers actively try to **bypass or disable SmartScreen** to deliver malware. SmartScreen bypass techniques are common in phishing and malware campaigns.
Risk Summary
HIGH priority for SOC triage. smartscreen.exe is a critical security feature. Monitor for attempts to disable SmartScreen via registry or Group Policy. SmartScreen not running or disabled is a significant security gap.
Overview
What is smartscreen.exe?
SmartScreen protects Windows users from malicious content.
Core Functions
Protection Features:
- Check downloaded files reputation
- Block malicious websites
- Warn about unknown apps
- Protect Microsoft Edge
Security Significance
- Download Protection: Blocks known malware
- Phishing Protection: Warns of malicious sites
- Attack Target: Attackers try to disable
Normal Behavior
Normal Behavior
Expected Process State
| Property | Expected Value |
|---|---|
| Path | C:\Windows\System32\smartscreen.exe |
| Parent | svchost.exe or explorer.exe |
| User | Current user |
| Trigger | On file download/execution |
Common Locations
C:\Windows\System32\smartscreen.exeSuspicious Indicators
Legitimate vs Suspicious
LEGITIMATE
Path: C:\Windows\System32\smartscreen.exe
Context: Triggered by downloads
Status: Enabled
SUSPICIOUS
Path: C:\Windows\smartscreen.exe
Status: Disabled via registry
Not triggering on downloads
Context: Disabled before malware execution
Abuse Techniques
Attack Techniques
Technique #1: SmartScreen Bypass (T1553.005)
Disable via Registry:
reg add "HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer" /v SmartScreenEnabled /t REG_SZ /d Off
Technique #2: Zone.Identifier Removal (T1553.005)
Remove Mark-of-the-Web to bypass SmartScreen:
Remove-Item -Path $file -Stream Zone.Identifier
Technique #3: Trusted Signers
Using signed binaries to avoid SmartScreen.
Detection Guidance
Detection Strategies
Priority #1: SmartScreen Disabled
RegistryModification CONTAINS "SmartScreenEnabled" AND
Value = "Off"
→ ALERT: CRITICAL
Priority #2: Zone.Identifier Removal
FileStream = "Zone.Identifier" AND
Action = "Delete"
→ ALERT: HIGH
Remediation Steps
Protection and Remediation
Defense: Enforce SmartScreen
Use Group Policy to prevent disabling SmartScreen.
If Compromise Suspected
- Verify SmartScreen is enabled
- Check registry settings
- Review recent downloads
- Re-enable if disabled
Investigation Checklist
Investigation Checklist
- Verify SmartScreen is enabled
- Check registry for disable flags
- Review Zone.Identifier removals
- Check recent downloads
MITRE ATT&CK Techniques
Last verified: January 18, 2026