Windows: Impacket Tool Execution

Rule ID

PH_Rule_SIGMA_1341

Default Status

Enabled

Description

Detects the execution of different compiled Windows binaries of the impacket toolset (based on names or part of their names - could lead to false positives). This rule is adapted from https://github.com/SigmaHQ/sigma/blob/master/rules/windows/process_creation/proc_creation_win_hktl_impacket_tools.yml

Severity

MITRE ATT&CK® Tactics

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/TA0009

MITRE ATT&CK® Techniques

T1557.001

Man-in-the-Middle: LLMNR/NBT-NS Poisoning and SMB Relay

Adversaries may attempt to position themselves between two or more networked devices using a man-in-the-middle (MiTM) technique to support follow-on behaviors such as Network Sniffing or Transmitted Data Manipulation. By responding to Link-Local Multicast Name Resolution (LLMNR) and NetBIOS Name Service (NBT-NS) network traffic, adversaries may spoof an authoritative source for name resolution to force communication with an adversary controlled system. This activity may be used to collect or relay authentication materials.

https://attack.mitre.org/techniques/T1557/001

Impacts

Server

Data Source

Windows Sysmon 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="Win-Sysmon-1-Create-Process" AND (procName REGEXP ".*\\goldenPac.*|.*\\karmaSMB.*|.*\\kintercept.*|.*\\ntlmrelayx.*|.*\\rpcdump.*|.*\\samrdump.*|.*\\secretsdump.*|.*\\smbexec.*|.*\\smbrelayx.*|.*\\wmiexec.*|.*\\wmipersist.*" OR procName REGEXP "\\GetADUsers_windows\.exe$|\\GetNPUsers_windows\.exe$|\\GetUserSPNs_windows\.exe$|\\atexec_windows\.exe$|\\dcomexec_windows\.exe$|\\dpapi_windows\.exe$|\\findDelegation_windows\.exe$|\\getPac_windows\.exe$|\\getST_windows\.exe$|\\getTGT_windows\.exe$|\\ifmap_windows\.exe$|\\mimikatz_windows\.exe$|\\netview_windows\.exe$|\\nmapAnswerMachine_windows\.exe$|\\opdump_windows\.exe$|\\psexec_windows\.exe$|\\rdp_check_windows\.exe$|\\sambaPipe_windows\.exe$|\\smbclient_windows\.exe$|\\smbserver_windows\.exe$|\\sniff_windows\.exe$|\\sniffer_windows\.exe$|\\split_windows\.exe$|\\ticketer_windows\.exe$")

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,procName

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,
procName = Filter.procName

FortiSIEM Rules