From afb00d70975e37c2654ecff5f44d176aeeff08c8 Mon Sep 17 00:00:00 2001
From: Samirbous <64742097+Samirbous@users.noreply.github.com>
Date: Tue, 8 Dec 2020 20:51:14 +0100
Subject: [PATCH] [New Rule] Encoded Executable Stored in the Registry (#636)

* [New Rule] Encoded Executable Stored in the Registry

* eql syntax

* ecs_version

* Update rules/windows/defense_evasion_hide_encoded_executable_registry.toml

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

* Update rules/windows/defense_evasion_hide_encoded_executable_registry.toml

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

Co-authored-by: Brent Murphy <56412096+bm11100@users.noreply.github.com>
---
 ...sion_hide_encoded_executable_registry.toml | 41 +++++++++++++++++++
 1 file changed, 41 insertions(+)
 create mode 100644 rules/windows/defense_evasion_hide_encoded_executable_registry.toml

diff --git a/rules/windows/defense_evasion_hide_encoded_executable_registry.toml b/rules/windows/defense_evasion_hide_encoded_executable_registry.toml
new file mode 100644
index 000000000..85fe52dfd
--- /dev/null
+++ b/rules/windows/defense_evasion_hide_encoded_executable_registry.toml
@@ -0,0 +1,41 @@
+[metadata]
+creation_date = "2020/11/25"
+maturity = "production"
+updated_date = "2020/11/25"
+
+[rule]
+author = ["Elastic"]
+description = """
+Identifies registry write modifications to hide an encoded portable executable. This could be indicative of adversary
+defense evasion by avoiding the storing of malicious content directly on disk.
+"""
+from = "now-9m"
+index = ["logs-endpoint.events.*", "winlogbeat-*"]
+language = "eql"
+license = "Elastic License"
+name = "Encoded Executable Stored in the Registry"
+risk_score = 47
+rule_id = "93c1ce76-494c-4f01-8167-35edfb52f7b1"
+severity = "medium"
+tags = ["Elastic", "Host", "Windows", "Threat Detection", "Defense Evasion"]
+type = "eql"
+
+query = '''
+registry where
+/* update here with encoding combinations */
+ registry.data.strings : "TVqQAAMAAAAEAAAA*"
+'''
+
+
+[[rule.threat]]
+framework = "MITRE ATT&CK"
+[[rule.threat.technique]]
+id = "T1140"
+name = "Deobfuscate/Decode Files or Information"
+reference = "https://attack.mitre.org/techniques/T1140/"
+
+
+[rule.threat.tactic]
+id = "TA0005"
+name = "Defense Evasion"
+reference = "https://attack.mitre.org/tactics/TA0005/"