This file, "Download File Steam id change v2.0 by ostrog.rar," is highly likely a or a phishing scam . You should not download or run it. Why this is a High-Risk File

If you have already run this file, immediately change your Steam password and use the "Sign out everywhere" option on your Authorized Devices page. Account Security Recommendations - Steam Support

If your goal was to change your identity on Steam, use these legitimate, built-in methods: