Medium RiskWindowsLegitimateCommonly Abused
steam.exeGAMING PLATFORMsteam.exe - Steam Gaming Platform Security Analysis
steam.exe is the **Steam gaming platform client** by Valve. Attackers target Steam for **account theft**, **game item fraud**, and **malware distribution** via fake game mods. Steam's popularity makes it a valuable target for credential stealers and phishing attacks.
Risk Summary
MEDIUM priority for SOC triage. steam.exe is a legitimate gaming client that is frequently targeted for credential theft. Monitor for Steam credential file access by non-Steam processes and Steam running from unusual locations.
Overview
What is steam.exe?
Steam is a digital gaming platform by Valve Corporation.
Core Functions
Gaming Services:
- Game distribution
- Social features
- In-game purchases
- Cloud saves
Security Significance
- Account Value: Games and items worth money
- Credential Target: Login theft common
- Mod Risk: Malicious mods exist
Normal Behavior
Normal Behavior
Expected Process State
| Property | Expected Value |
|---|---|
| Path | C:\Program Files (x86)\Steam\steam.exe |
| Parent | explorer.exe |
| User | Logged-in user |
| Network | Valve servers |
Credential Location
C:\Program Files (x86)\Steam\config\loginusers.vdf
Common Locations
C:\Program Files (x86)\Steam\steam.exeC:\Program Files\Steam\steam.exeSuspicious Indicators
Legitimate vs Suspicious
LEGITIMATE
Path: C:\Program Files*\Steam\steam.exe
Parent: explorer.exe
Network: Valve/Steam servers
SUSPICIOUS
Path: C:\Users\*\steam.exe
C:\Temp\steam.exe
Behavior: loginusers.vdf accessed by other process
ssfn* files copied
Abuse Techniques
Attack Techniques
Technique #1: Credential Theft (T1555)
Stealing Steam Credentials:
- loginusers.vdf contains tokens
- ssfn* files for auth
Technique #2: Phishing (T1566)
Fake Steam login pages.
Technique #3: Malicious Mods
Malware distributed as game mods.
Detection Guidance
Detection Strategies
Priority #1: Credential File Access
Process != "steam.exe" AND
FileAccess CONTAINS ["loginusers.vdf", "ssfn"]
→ ALERT: HIGH - Steam credential theft
Priority #2: Path Verification
Process = "steam.exe" AND
Path NOT CONTAINS "Program Files"
→ ALERT: HIGH
Remediation Steps
Protection and Remediation
Defense: Steam Guard
Enable Steam Guard two-factor authentication.
If Compromise Suspected
- Change Steam password
- Deauthorize all devices
- Enable Steam Guard
- Review recent trades/purchases
Investigation Checklist
Investigation Checklist
- Verify steam.exe path
- Check for credential file access
- Review login history
- Check for unauthorized purchases
MITRE ATT&CK Techniques
Last verified: January 18, 2026