PH_Rule_SIGMA_1918
Enabled
Detect suspicious LDAP request from non-Windows application. This rule is adapted from https://github.com/SigmaHQ/sigma/blob/master/rules/windows/dns_query/dns_query_win_susp_ldap.yml
5
Security
Discovery
Discovery consists of techniques an adversary may use to gain knowledge about the system and internal network. These techniques help adversaries observe the environment and orient themselves before deciding how to act. They also allow adversaries to explore what they can control and what’s around their entry point in order to discover how it could benefit their current objective. Native operating system tools are often used toward this post-compromise information-gathering objective.
https://attack.mitre.org/tactics/TA0007T1482
Domain Trust Discovery
Adversaries may attempt to gather information on domain trust relationships that may be used to identify lateral movement opportunities in Windows multi-domain/forest environments. Domain trusts provide a mechanism for a domain to allow access to resources based on the authentication procedures of another domain. Domain trusts allow the users of the trusted domain to access resources in the trusting domain. The information discovered may help the adversary conduct SID-History Injection, Pass the Ticket, and Kerberoasting.
https://attack.mitre.org/techniques/T1482Server
Windows Sysmon via FortiSIEM Agent
Correlation
No remediation guidance specified
If the following pattern or patterns match an ingested event within the given time window in seconds, trigger an incident.
300 seconds
If the following defined pattern/s occur within a 300 second time window.
Filter
This is the named definition of the event query, this is important if multiple subpatterns are defined to distinguish them.
This is the query logic that matches incoming events
eventType="Win-Sysmon-22-DNS-Query" AND queryId REGEXP "^_ldap\." AND ((procName NOT REGEXP "^C:\\Windows\\") AND (procName NOT REGEXP "^C:\\Program Files \(x86\)\\Windows Defender\\MsMpEng\.exe|^C:\\Program Files\\Windows Defender\\MsMpEng\.exe|^C:\\ProgramData\\Microsoft\\Windows Defender\\Platform\\" OR procName NOT REGEXP "\\MsMpEng\.exe$") AND (procName!="<unknown process>") AND (procName NOT REGEXP "^C:\\WindowsAzure\\GuestAgent"))
This defines how matching events are aggregated, only events with the same matching attribute values are grouped into one unique incident ID
hostName,procName,queryId
This is most typically a numerical constraint that defines when the rule should trigger an incident
COUNT(*) >= 1
This section defines which fields in matching raw events should be mapped to the incident attributes in the resulting incident.
The available raw event attributes to map are limited to the group by attributes and the aggregate event constraint fields for each subpattern
hostName = Filter.hostName,
procName = Filter.procName,
queryId = Filter.queryId