...
Data ingestion method: Azure Functions and the REST API.
Supported by: Alcide
Common Event Format
Common Event Format (CEF) is an industry standard format on top of Syslog messages, used by many security vendors to allow event interoperability among different platforms. By connecting your CEF logs to Azure Sentinel, you can take advantage of search & correlation, alerting, and threat intelligence enrichment for each log.
Syslog Connector
https://docs.microsoft.com/en-us/azure/sentinel/connect-syslog
Install the Linux agent
| Code Block |
|---|
wget https://raw.githubusercontent.com/Microsoft/OMS-Agent-for-Linux/master/installer/scripts/onboard_agent.sh && sh onboard_agent.sh -w xxx -s xxx -d opinsights.azure.com |
...
| Code Block |
|---|
$ sudo /opt/microsoft/omsagent/bin/uninstall
# Purge - might be the better way to uninstall
$ wget -O onboard_agent.sh https://raw.githubusercontent.com/Microsoft/OMS-Agent-for-Linux/master/installer/scripts/onboard_agent.sh && sudo sh onboard_agent.sh --purge
|
Query Examples
| Code Block |
|---|
Syslog
| where Facility in ("authpriv","auth")
| extend c = extract( "Accepted\\s(publickey|password|keyboard-interactive/pam)\\sfor ([^\\s]+)",1,SyslogMessage)
| where isnotempty(c)
| count
Syslog
| where Facility in ("authpriv","auth")
| where SyslogMessage contains "authentication failure "
| count
// Search in multiple tables
// Search both Syslog and Event tables for the term "login".
search in (Syslog, Event) "authentication failure"
| where TimeGenerated > ago(24h) // return records from the last 24 hours
// All Syslog with errors
// Last 100 Syslog with erros.
Syslog
| where SeverityLevel == "err" or SeverityLevel == "error"
| top 100 by TimeGenerated desc
//login errors
Syslog
| where SeverityLevel == "err" or SeverityLevel == "error"
| where Facility == "auth"
| where SyslogMessage contains "kex_exchange_identification"
//any auth errors
Syslog
| where SeverityLevel == "err" or SeverityLevel == "error"
| where Facility == "auth"
| count
//failed login
Syslog
| where Facility == "auth"
| where SyslogMessage contains "Failed password"
| order by EventTime asc
| count
//failed login with extraction of fields
Syslog
| where Facility == "auth"
| where SyslogMessage contains "Failed password"
| extend user = extract("Failed password for invalid user (.*) from (.*) port (.*) (.*)", 1, SyslogMessage, typeof(string))
| extend remoteIp = extract("Failed password for invalid user (.*) from (.*) port (.*) (.*)", 2, SyslogMessage, typeof(string))
| extend port = extract("Failed password for invalid user (.*) from (.*) port (.*) (.*)", 3, SyslogMessage, typeof(string))
| extend protocol = extract("Failed password for invalid user (.*) from (.*) port (.*) (.*)", 4, SyslogMessage, typeof(string))
| order by EventTime asc
|
...