PH_Rule_TH_Linux_1
Enabled
Detects tcpdump program running on a Linux host. Tcpdump is a network monitoring or packet sniffing tool that can be used to capture insecure credentials or data in motion. Sniffing can also be used to discover details of network services as a prelude to lateral movement or defense evasion. Some normal use of this command may originate from server or network administrators engaged in network troubleshooting. This requires process monitoring via FortiSIEM Linux agent.
5
Security
Credential Access
Credential Access consists of techniques for stealing credentials like account names and passwords. Techniques used to get credentials include keylogging or credential dumping. Using legitimate credentials can give adversaries access to systems, make them harder to detect, and provide the opportunity to create more accounts to help achieve their goals.
https://attack.mitre.org/tactics/TA0006T1040
Network Sniffing
Adversaries may sniff network traffic to capture information about an environment, including authentication material passed over the network. Network sniffing may also reveal configuration details, such as running services, version numbers, and other network characteristics necessary for subsequent Lateral Movement and/or Defense Evasion activities.
https://attack.mitre.org/techniques/T1040Server
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 = "tcpdump"
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