From 97fa6c62cdb4a5147ced1e5dfe71545870c91d8f Mon Sep 17 00:00:00 2001
From: Samirbous <64742097+Samirbous@users.noreply.github.com>
Date: Tue, 8 Dec 2020 21:28:28 +0100
Subject: [PATCH] [New Rule] Remote File Download via Powershell (#660)

* [New Rule] Remote File Download via Powershell

* new line

* eql syntax

* ecs_version

* added google related FPs

* Update rules/windows/command_and_control_remote_file_copy_powershell.toml

Co-authored-by: Justin Ibarra <brokensound77@users.noreply.github.com>

* Update rules/windows/command_and_control_remote_file_copy_powershell.toml

Co-authored-by: Justin Ibarra <brokensound77@users.noreply.github.com>

* Update rules/windows/command_and_control_remote_file_copy_powershell.toml

Co-authored-by: Brent Murphy <56412096+bm11100@users.noreply.github.com>

* Update rules/windows/command_and_control_remote_file_copy_powershell.toml

Co-authored-by: seth-goodwin <58222969+seth-goodwin@users.noreply.github.com>

* Update rules/windows/command_and_control_remote_file_copy_powershell.toml

Co-authored-by: seth-goodwin <58222969+seth-goodwin@users.noreply.github.com>

* relint

* ecs_version removed

* replaced path with name to avoid FPs for users temp folder

Co-authored-by: Justin Ibarra <brokensound77@users.noreply.github.com>
Co-authored-by: Brent Murphy <56412096+bm11100@users.noreply.github.com>
Co-authored-by: seth-goodwin <58222969+seth-goodwin@users.noreply.github.com>
---
 ...d_control_remote_file_copy_powershell.toml | 54 +++++++++++++++++++
 1 file changed, 54 insertions(+)
 create mode 100644 rules/windows/command_and_control_remote_file_copy_powershell.toml

diff --git a/rules/windows/command_and_control_remote_file_copy_powershell.toml b/rules/windows/command_and_control_remote_file_copy_powershell.toml
new file mode 100644
index 000000000..63ee46ce4
--- /dev/null
+++ b/rules/windows/command_and_control_remote_file_copy_powershell.toml
@@ -0,0 +1,54 @@
+[metadata]
+creation_date = "2020/11/30"
+maturity = "production"
+updated_date = "2020/11/30"
+
+[rule]
+author = ["Elastic"]
+description = "Identifies powershell.exe being used to download an executable file from an untrusted remote destination."
+from = "now-9m"
+index = ["winlogbeat-*", "logs-endpoint.events.*"]
+language = "eql"
+license = "Elastic License"
+name = "Remote File Download via PowerShell"
+risk_score = 47
+rule_id = "33f306e8-417c-411b-965c-c2812d6d3f4d"
+severity = "medium"
+tags = ["Elastic", "Host", "Windows", "Threat Detection", "Command and Control"]
+type = "eql"
+
+query = '''
+sequence by host.id, process.entity_id with maxspan=30s
+  [network where process.name : "powershell.exe" and network.protocol == "dns" and
+   not dns.question.name : ("localhost", "*.microsoft.com", "*.azureedge.net", "*.powershellgallery.com", "*.windowsupdate.com", "metadata.google.internal") and 
+   not user.domain : "NT AUTHORITY"]
+    [file where process.name : "powershell.exe" and event.type == "creation" and file.extension : ("exe", "dll", "ps1", "bat") and 
+   not file.name : "__PSScriptPolicy*.ps1"]
+'''
+
+
+[[rule.threat]]
+framework = "MITRE ATT&CK"
+[[rule.threat.technique]]
+id = "T1105"
+name = "Ingress Tool Transfer"
+reference = "https://attack.mitre.org/techniques/T1105/"
+
+
+[rule.threat.tactic]
+id = "TA0011"
+name = "Command and Control"
+reference = "https://attack.mitre.org/tactics/TA0011/"
+[[rule.threat]]
+framework = "MITRE ATT&CK"
+[[rule.threat.technique]]
+id = "T1086"
+name = "PowerShell"
+reference = "https://attack.mitre.org/techniques/T1086/"
+
+
+[rule.threat.tactic]
+id = "TA0002"
+name = "Execution"
+reference = "https://attack.mitre.org/tactics/TA0002/"
+