Web app services keep going down

Question

Our azure app services keep going down every 2 hours. We think it is a malware attack. How to get rid of it ?

Answer 1

Hi @Harjeet singh
 I understand your Azure App Services going down every few hours is frustrating. While a malware attack is possible, there are several troubleshooting steps you can follow to address this issue.

HTTP 5xx errors may signal unhandled exceptions. Make sure errors are logged properly, and consider using Application Insights to track issues.

Monitor CPU and memory usage in the Azure portal. If your app hits resource limits, scaling up or adding more instances may help.

Apps may restart for various reasons. Use the "Diagnose and solve problems" tool and the Web App Restarted detector to review restart causes and timelines.

Health checks can help manage restarts by letting the platform know when your app is ready to handle traffic.

If malware is a concern, review your security settings, enable WAF rules if available, and scan for vulnerabilities regularly.

Check logs for any suspicious login attempts or activities that could indicate an attack.
Let me know if you have any further assistances
https://learn.microsoft.com/en-us/azure/app-service/overview#troubleshooting
https://learn.microsoft.com/en-us/azure/app-service/routine-maintenance-downtime
https://learn.microsoft.com/en-us/azure/azure-monitor/app/app-insights-overview

Answer 2

If your Azure App Services are going down every 2 hours, it’s essential to investigate the root cause. While you suspect a malware attack, it’s crucial to ensure your web app's code is secure and up to date. Here are steps you can take to address the issue:

1. Review Logs: Check the web app's HTTP logs and deployment history to identify any unusual patterns or when the issues began. This can help determine if there was a specific event that triggered the downtime.
2. Update Code: Ensure that your application code is updated to fix any vulnerabilities that could be exploited. An outdated app package can lead to security issues.
3. Implement Security Measures: Consider configuring security services such as Web Application Firewall (WAF) and Microsoft Defender for App Service to protect against attacks.
4. Monitor Performance: Use Azure's monitoring tools to keep track of your app's performance and health. Setting up health checks can help automatically replace unresponsive instances.
5. Backup and Restore: If you suspect that your app has been compromised, you may want to restore a backup or redeploy the site after ensuring that vulnerabilities are addressed.
6. Contact Azure Support: If the problem persists, reach out to Azure support for assistance in reviewing your app's security and performance issues.

By taking these steps, you can work towards resolving the issues with your Azure App Services and enhancing their security against potential attacks.

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References:

• FAQs
• Troubleshoot slow app performance issues in Azure App Service