PH_Rule_SIGMA_2299
Enabled
Detect the usage of "DirLister.exe" a utility for quickly listing folder or drive contents. It was seen used by BlackCat ransomware to create a list of accessible directories and files. This rule is adapted from https://github.com/SigmaHQ/sigma/blob/master/rules/windows/process_creation/proc_creation_win_dirlister_execution.yml
3
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/TA0007T1083
File and Directory Discovery
Adversaries may enumerate files and directories or may search in specific locations of a host or network share for certain information within a file system. Adversaries may use this information during automated discovery to shape follow-on behaviors, including whether or not the adversary fully infects the target and/or attempts specific actions.
https://attack.mitre.org/techniques/T1083Server
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-1-Create-Process" AND (srcFileName="DirLister.exe" OR procName REGEXP "\\dirlister\.exe$")
This defines how matching events are aggregated, only events with the same matching attribute values are grouped into one unique incident ID
hostName,procName,srcFileName
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,
srcFileName = Filter.srcFileName