# Analyzing a Series of Failed Login Attempts from Multiple IP Addresses

A series of failed login attempts from multiple IP addresses could indicate a coordinated attack such as brute-force or password-spraying. Below is a systematic approach to analyze and respond to such activity effectively.

***

## **1. Aggregate and Correlate Logs**

* **Action:**
  * Collect logs related to failed login attempts (e.g., Event ID 4625 in Windows environments).
  * Aggregate these logs in a centralized system (SIEM or log management tool).
  * Filter and organize by key parameters such as:
    * IP addresses.
    * Targeted usernames.
    * Timestamps.
* **Purpose:** Identifies patterns and enables cross-event correlation for detecting attack behavior.

***

## **2. Identify Patterns**

* **Action:**
  * Look for repeated failed login attempts from:
    * The same IP address targeting multiple accounts.
    * Multiple IP addresses targeting a single account.
  * Examine:
    * The frequency and timing of login attempts (e.g., rapid bursts suggest automation).
    * Repeated use of common passwords across accounts.
* **Purpose:** Determines whether the activity is indicative of brute-force or password-spraying attacks.

***

## **3. Geo-Location Analysis**

* **Action:**
  * Cross-reference the IP addresses with GeoIP databases.
  * Determine if login attempts originate from:
    * Locations unexpected for the targeted users.
    * Known malicious regions or foreign locations unrelated to business operations.
* **Purpose:** Helps in identifying attacks originating from suspicious geographic areas.

***

## **4. Compare with Successful Logins**

* **Action:**
  * Search for successful login attempts that occur:
    * After repeated failures from the same IP address.
    * Using the same username as failed attempts but from a different IP.
  * Correlate these logs to check for signs of compromised accounts.
* **Purpose:** Identifies accounts that may have been breached following attack attempts.

***

## **5. Cross-Reference with Other Logs**

* **Action:**
  * Review additional log sources such as:
    * Firewall or intrusion detection/prevention system (IDS/IPS) logs.
    * VPN or RDP access logs.
    * Application-specific logs (e.g., web server logs for web application authentication attempts).
  * Check if the same IP addresses are:
    * Scanning the network.
    * Attempting connections through other means.
* **Purpose:** Provides a broader view of the attacker’s activity and potential infiltration paths.

***

## **6. Response Actions**

* **Block Offensive Activity:**
  * Add the offending IP addresses to blocklists at the firewall, WAF (Web Application Firewall), or IDS/IPS.
* **Secure Accounts:**
  * Reset passwords for the targeted accounts.
  * Enforce stronger security measures, such as:
    * Multi-factor authentication (MFA).
    * Account lockouts after repeated failed login attempts.
* **Strengthen Monitoring:**
  * Increase monitoring of affected systems and accounts for any further suspicious activity.
  * Set up real-time alerts for similar events in the future.

***

## **Conclusion**

By aggregating, correlating, and analyzing failed login attempts alongside other log sources, You  can identify attack patterns, detect compromised accounts, and implement effective mitigation measures. A proactive response, coupled with strengthened account and network security, is essential to prevent future incidents.


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://karim-ashraf.gitbook.io/karim_ashraf_space/writeups/advanced-log-analysis/analyzing-a-series-of-failed-login-attempts-from-multiple-ip-addresses.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.