PH_Rule_SIGMA_587
Enabled
Detects the use of rar.exe, on the command line, to create an archive with password protection or with a specific compression level. This is pretty indicative of malicious actions. This rule is adapted from https://github.com/SigmaHQ/sigma/blob/master/rules/windows/process_creation/proc_creation_win_rar_compression_with_password.yml
7
Security
Collection
Collection consists of techniques adversaries may use to gather information and the sources information is collected from that are relevant to following through on the adversary's objectives. Frequently, the next goal after collecting data is to steal (exfiltrate) the data. Common target sources include various drive types, browsers, audio, video, and email. Common collection methods include capturing screenshots and keyboard input.
https://attack.mitre.org/tactics/TA0009T1560.001
Archive Collected Data: Archive via Utility
An adversary may compress or encrypt data that is collected prior to exfiltration using 3rd party utilities. Many utilities exist that can archive data, including 7-Zip, WinRAR, and WinZip. Most utilities include functionality to encrypt and/or compress data.
https://attack.mitre.org/techniques/T1560/001Server
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 command REGEXP ".* -hp.*" AND command REGEXP ".* -m.*|.* a .*"
This defines how matching events are aggregated, only events with the same matching attribute values are grouped into one unique incident ID
command,hostName
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
command = Filter.command,
hostName = Filter.hostName