PH_Rule_TH_Linux_22
Enabled
Mknod Process Activity detected. Linux mknod program is sometimes used in the command payload of a remote command injection and other exploits. It is used to export a command shell when the traditional version of netcat is not available to the payload. Some normal use of this program, at varying levels of frequency, may originate from scripts, automation tools, and frameworks. This requires process monitoring via FortiSIEM Linux agent.
7
Security
Command And Control
T1071.004
Application Layer Protocol: DNS
Adversaries may communicate using the Domain Name System (DNS) application layer protocol to avoid detection/network filtering by blending in with existing traffic. Commands to the remote system, and often the results of those commands, will be embedded within the protocol traffic between the client and server.
https://attack.mitre.org/techniques/T1071/004Server
Linux Process Monitoring 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 = "LINUX_PROCESS_EXEC" AND procName = "mknod"
This defines how matching events are aggregated, only events with the same matching attribute values are grouped into one unique incident ID
hostName, user, procName, swParam
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,
user = Filter.user,
procName = Filter.procName,
swParam = Filter.swParam