From c76439923b02fac5567395e9bb2afff801404ea9 Mon Sep 17 00:00:00 2001
From: Samirbous <64742097+Samirbous@users.noreply.github.com>
Date: Tue, 8 Dec 2020 12:27:03 +0100
Subject: [PATCH] [New Rule] Attempt to Remove File Quarantine Attribute (#674)

* [New Rule] Attempt to Remove File Quarantine Attribute

* Update rules/macos/defense_evasion_attempt_del_quarantine_attrib.toml

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

* relinted

* Update rules/macos/defense_evasion_attempt_del_quarantine_attrib.toml

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

Co-authored-by: Brent Murphy <56412096+bm11100@users.noreply.github.com>
Co-authored-by: Justin Ibarra <brokensound77@users.noreply.github.com>
---
 ...evasion_attempt_del_quarantine_attrib.toml | 44 +++++++++++++++++++
 1 file changed, 44 insertions(+)
 create mode 100644 rules/macos/defense_evasion_attempt_del_quarantine_attrib.toml

diff --git a/rules/macos/defense_evasion_attempt_del_quarantine_attrib.toml b/rules/macos/defense_evasion_attempt_del_quarantine_attrib.toml
new file mode 100644
index 000000000..b10570bc8
--- /dev/null
+++ b/rules/macos/defense_evasion_attempt_del_quarantine_attrib.toml
@@ -0,0 +1,44 @@
+[metadata]
+creation_date = "2020/08/14"
+maturity = "production"
+updated_date = "2020/11/03"
+
+[rule]
+author = ["Elastic"]
+description = """
+Identifies a potential Gatekeeper bypass. In macOS, when applications or programs are downloaded from the internet,
+there is a quarantine flag set on the file. This attribute is read by Apple's Gatekeeper defense program at execution
+time. An adversary may disable this attribute to evade defenses.
+"""
+from = "now-9m"
+index = ["auditbeat-*", "logs-endpoint.events.*"]
+language = "eql"
+license = "Elastic License"
+name = "Attempt to Remove File Quarantine Attribute"
+references = [
+    "https://www.trendmicro.com/en_us/research/20/k/new-macos-backdoor-connected-to-oceanlotus-surfaces.html",
+]
+risk_score = 43
+rule_id = "f0b48bbc-549e-4bcf-8ee0-a7a72586c6a7"
+severity = "medium"
+tags = ["Elastic", "Host", "macOS", "Threat Detection", "Defense Evasion"]
+type = "eql"
+
+query = '''
+process where event.type in ("start", "process_started") and
+  process.name == "xattr" and process.args == "com.apple.quarantine" and process.args == "-d"
+'''
+
+
+[[rule.threat]]
+framework = "MITRE ATT&CK"
+[[rule.threat.technique]]
+id = "T1089"
+name = "Disabling Security Tools"
+reference = "https://attack.mitre.org/techniques/T1089/"
+
+
+[rule.threat.tactic]
+id = "TA0005"
+name = "Defense Evasion"
+reference = "https://attack.mitre.org/tactics/TA0005/"