Files
sigma-rules/rules/windows/discovery_posh_suspicious_api_functions.toml
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Jonhnathan 49854aaae2 [Rule Tuning] Add Investigation Guides, Config/Logging Policy to PowerShell merged rules (#1610)
* Add Investigation Guide and config to Suspicious Portable Executable Encoded in Powershell Script

* Add Investigation Guide and config to "PowerShell Suspicious Discovery Related Windows API Functions" rule

* Add Investigation Guide and Config to "PowerShell MiniDump Script" rule

* Add logging policy reference

* Add Investigation Guide/Config to "PowerShell Suspicious Script with Audio Capture Capabilities"

* Add Related Rules GUIDs

* Add Investigation Guide/config for "Potential Process Injection via PowerShell"

* Adjust Response and remediation

* Add Investigation Guide/config for "PowerShell Keylogging Script"

* bump updated_date

* Apply suggestions from Samir

Co-authored-by: Samirbous <64742097+Samirbous@users.noreply.github.com>

* Apply suggestions

* Revise line from investigation guides

Co-authored-by: Justin Ibarra <brokensound77@users.noreply.github.com>
Co-authored-by: Samirbous <64742097+Samirbous@users.noreply.github.com>
2022-01-20 08:56:53 -03:00

142 lines
4.2 KiB
TOML

[metadata]
creation_date = "2021/10/13"
maturity = "production"
updated_date = "2021/11/30"
[rule]
author = ["Elastic"]
description = """
This rule detects the use of discovery-related Windows API functions in PowerShell Scripts. Attackers can use these
functions to perform various situational awareness related activities, like enumerating users, shares, sessions, domain
trusts, groups, etc.
"""
false_positives = ["Legitimate Powershell Scripts that make use of these Functions"]
from = "now-9m"
index = ["winlogbeat-*", "logs-windows.*"]
language = "kuery"
license = "Elastic License v2"
name = "PowerShell Suspicious Discovery Related Windows API Functions"
note = """## Triage and analysis.
### Investigating PowerShell Suspicious Discovery Related Windows API Functions
PowerShell is one of the main tools used by system administrators for automation, report routines, and other tasks.
Attackers can use PowerShell to interact with the Win32 API to bypass file based AntiVirus detections, using libraries
like PSReflect or Get-ProcAddress Cmdlet.
#### Possible investigation steps:
- Examine script content that triggered the detection.
- Investigate script execution chain (parent process tree).
- Inspect any file or network events from the suspicious powershell host process instance.
- If the action is suspicious for the user, check for any other activities done by the user in the last 48 hours.
### False Positive Analysis
- Verify whether the script content is malicious/harmful.
### Related Rules
- PowerShell PSReflect Script - 56f2e9b5-4803-4e44-a0a4-a52dc79d57fe
### Response and Remediation
- Immediate response should be taken to validate, investigate, and potentially contain the activity to prevent further
post-compromise behavior.
## Config
The 'PowerShell Script Block Logging' logging policy must be enabled.
Steps to implement the logging policy with with Advanced Audit Configuration:
```
Computer Configuration >
Administrative Templates >
Windows PowerShell >
Turn on PowerShell Script Block Logging (Enable)
```
Steps to implement the logging policy via registry:
```
reg add "hklm\\SOFTWARE\\Policies\\Microsoft\\Windows\\PowerShell\\ScriptBlockLogging" /v EnableScriptBlockLogging /t REG_DWORD /d 1
```
"""
references = [
"https://github.com/BC-SECURITY/Empire/blob/9259e5106986847d2bb770c4289c0c0f1adf2344/data/module_source/situational_awareness/network/powerview.ps1#L21413",
"https://github.com/atc-project/atc-data/blob/master/docs/Logging_Policies/LP_0109_windows_powershell_script_block_log.md"
]
risk_score = 47
rule_id = "61ac3638-40a3-44b2-855a-985636ca985e"
severity = "medium"
tags = ["Elastic", "Host", "Windows", "Threat Detection", "Discovery"]
timestamp_override = "event.ingested"
type = "query"
query = '''
event.category:process and
powershell.file.script_block_text : (
NetShareEnum or
NetWkstaUserEnum or
NetSessionEnum or
NetLocalGroupEnum or
NetLocalGroupGetMembers or
DsGetSiteName or
DsEnumerateDomainTrusts or
WTSEnumerateSessionsEx or
WTSQuerySessionInformation or
LsaGetLogonSessionData or
QueryServiceObjectSecurity
)
'''
[[rule.threat]]
framework = "MITRE ATT&CK"
[[rule.threat.technique]]
id = "T1135"
name = "Network Share Discovery"
reference = "https://attack.mitre.org/techniques/T1135/"
[[rule.threat.technique]]
id = "T1069"
name = "Permission Groups Discovery"
reference = "https://attack.mitre.org/techniques/T1069/"
[[rule.threat.technique.subtechnique]]
id = "T1069.001"
name = "Local Groups"
reference = "https://attack.mitre.org/techniques/T1069/001/"
[rule.threat.tactic]
id = "TA0007"
name = "Discovery"
reference = "https://attack.mitre.org/tactics/TA0007/"
[[rule.threat]]
framework = "MITRE ATT&CK"
[[rule.threat.technique]]
id = "T1059"
name = "Command and Scripting Interpreter"
reference = "https://attack.mitre.org/techniques/T1059/"
[[rule.threat.technique.subtechnique]]
id = "T1059.001"
name = "PowerShell"
reference = "https://attack.mitre.org/techniques/T1059/001/"
[[rule.threat.technique]]
id = "T1106"
name = "Native API"
reference = "https://attack.mitre.org/techniques/T1106/"
[rule.threat.tactic]
id = "TA0002"
name = "Execution"
reference = "https://attack.mitre.org/tactics/TA0002/"