:warning: THIS IS A EXPERIMENTAL DETECTION

This detection has been marked experimental by the Splunk Threat Research team. This means we have not been able to test, simulate, or build datasets for this detection. Use at your own risk. This analytic is NOT supported.

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Description

The following analytic detects long URLs that contain multiple SQL commands. A proactive approach helps to detect and respond to potential threats earlier, mitigating the risks associated with SQL injection attacks. This detection is made by a Splunk query that searches for web traffic data where the destination category is a web server and the URL length is greater than 1024 characters or the HTTP user agent length is greater than 200 characters. This detection is important because it suggests that an attacker is attempting to exploit a web application through SQL injection. SQL injection is a common technique used by attackers to exploit vulnerabilities in web applications and gain unauthorized access to databases. Attackers can insert malicious SQL commands into a URL to manipulate the application's database and retrieve sensitive information or modify data. The impact of a successful SQL injection attack can be severe, potentially leading to data breaches, unauthorized access, and even complete compromise of the affected system. False positives might occur since the legitimate use of web applications or specific URLs in your environment can trigger the detection. Therefore, you must review and validate any alerts generated by this analytic before taking any action. Next steps include reviewing the source and destination of the web traffic, as well as the specific URL and HTTP user agent. Additionally, capture and analyze any relevant on-disk artifacts and review concurrent processes to determine the source of the attack.

  • Type: TTP
  • Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
  • Datamodel: Web
  • Last Updated: 2022-03-28
  • Author: Bhavin Patel, Splunk
  • ID: e0aad4cf-0790-423b-8328-7564d0d938f9

Annotations

ATT&CK

ATT&CK

ID Technique Tactic
T1190 Exploit Public-Facing Application Initial Access
Kill Chain Phase
  • Delivery
NIST
  • DE.CM
CIS20
  • CIS 13
CVE
1
2
3
4
5
6
7
| tstats `security_content_summariesonly` count from datamodel=Web where Web.dest_category=web_server AND (Web.url_length > 1024 OR Web.http_user_agent_length > 200) by Web.src Web.dest Web.url Web.url_length Web.http_user_agent 
| `drop_dm_object_name("Web")` 
| eval url=lower(url) 
| eval num_sql_cmds=mvcount(split(url, "alter%20table")) + mvcount(split(url, "between")) + mvcount(split(url, "create%20table")) + mvcount(split(url, "create%20database")) + mvcount(split(url, "create%20index")) + mvcount(split(url, "create%20view")) + mvcount(split(url, "delete")) + mvcount(split(url, "drop%20database")) + mvcount(split(url, "drop%20index")) + mvcount(split(url, "drop%20table")) + mvcount(split(url, "exists")) + mvcount(split(url, "exec")) + mvcount(split(url, "group%20by")) + mvcount(split(url, "having")) + mvcount(split(url, "insert%20into")) + mvcount(split(url, "inner%20join")) + mvcount(split(url, "left%20join")) + mvcount(split(url, "right%20join")) + mvcount(split(url, "full%20join")) + mvcount(split(url, "select")) + mvcount(split(url, "distinct")) + mvcount(split(url, "select%20top")) + mvcount(split(url, "union")) + mvcount(split(url, "xp_cmdshell")) - 24 
| where num_sql_cmds > 3 
| `sql_injection_with_long_urls_filter`

Macros

The SPL above uses the following Macros:

:information_source: sql_injection_with_long_urls_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Required fields

List of fields required to use this analytic.

  • _time
  • Web.dest_category
  • Web.url_length
  • Web.http_user_agent_length
  • Web.src
  • Web.dest
  • Web.url
  • Web.http_user_agent

How To Implement

To successfully implement this search, you need to be monitoring network communications to your web servers or ingesting your HTTP logs and populating the Web data model. You must also identify your web servers in the Enterprise Security assets table.

Known False Positives

It's possible that legitimate traffic will have long URLs or long user agent strings and that common SQL commands may be found within the URL. Please investigate as appropriate.

Associated Analytic Story

RBA

Risk Score Impact Confidence Message
25.0 50 50 SQL injection attempt with url $url$ detected on $dest$

:information_source: The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.

Reference

Test Dataset

Replay any dataset to Splunk Enterprise by using our replay.py tool or the UI. Alternatively you can replay a dataset into a Splunk Attack Range

source | version: 3