Linux: NMAP Process Activity

Rule ID

PH_Rule_TH_Linux_24

Default Status

Enabled

Description

NMAP Process Activity detected. NMAP is a tool for network scanning and security testing. It can map and discover networks, and identify listening services and operating systems. It is sometimes used to gather information in support of exploitation, execution or lateral movement. Some normal use of this command may originate from security engineers and network or server administrators. Use of nmap by ordinary users is uncommon. This requires process monitoring via FortiSIEM Linux agent.

Severity

MITRE ATT&CK® Tactics

Reconnaissance

Reconnaissance consists of techniques that involve adversaries actively or passively gathering information that can be used to support targeting. Such information may include details of the victim organization, infrastructure, or staff/personnel. This information can be leveraged by the adversary to aid in other phases of the adversary lifecycle, such as using gathered information to plan and execute Initial Access, to scope and prioritize post-compromise objectives, or to drive and lead further Reconnaissance efforts.

https://attack.mitre.org/tactics/TA0043

MITRE ATT&CK® Techniques

T1592.002

Gather Victim Host Information: Software

Before compromising a victim, adversaries may gather information about the victim's host software that can be used during targeting. Information about installed software may include a variety of details such as types and versions on specific hosts, as well as the presence of additional components that might be indicative of added defensive protections (ex: antivirus, SIEMs, etc.).

https://attack.mitre.org/techniques/T1592/002

T1595.001

Active Scanning: Scanning IP Blocks

Before compromising a victim, adversaries may scan victim IP blocks to gather information that can be used during targeting. Public IP addresses may be allocated to organizations by block, or a range of sequential addresses.

https://attack.mitre.org/techniques/T1595/001

Impacts

Server

Data Source

Linux Process Monitoring via FortiSIEM Agent

Detection

Correlation

Remediation Guidance

No remediation guidance specified

Time Window

If the following pattern or patterns match an ingested event within the given time window in seconds, trigger an incident.

300 seconds

Trigger Conditions

If the following defined pattern/s occur within a 300 second time window.

Filter

SubPattern Definitions

SubPattern Name: Filter

This is the named definition of the event query, this is important if multiple subpatterns are defined to distinguish them.

SubPattern Query

This is the query logic that matches incoming events

eventType = "LINUX_PROCESS_EXEC" AND procName = "nmap"

Group by Attributes

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

Aggregate Constraint

This is most typically a numerical constraint that defines when the rule should trigger an incident

COUNT(*) >= 1

Incident Attribute Mapping

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

FortiSIEM Rules