PH_Rule_TH_Linux_21
Enabled
Potential DNS Tunneling via Iodine detected. Iodine is a tool for tunneling Internet protocol version 4 (IPV4) traffic over the DNS protocol to circumvent firewalls, network security groups, and network access lists while evading detection. 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 IN ("iodine", "iodined")
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