[New Rule] - MacOS Keychains compression

rules/macos/exfiltration_compress_credentials_keychains.toml

@@ -0,0 +1,43 @@
+[metadata]
+creation_date = "2020/08/14"
+ecs_version = ["1.6.0"]
+maturity = "production"
+updated_date = "2020/08/14"
+
+[rule]
+author = ["Elastic"]
+description = """
+Adversaries may collect the keychain storage data from a system to acquire credentials. Keychains are the built-in way
+for macOS to keep track of users' passwords and credentials for many services and features such as WiFi passwords,
+websites, secure notes, certificates, and Kerberos.
+"""
+index = ["auditbeat-*", "logs-endpoint.events.*"]
+language = "kuery"
+license = "Elastic License"
+name = "Compression of Keychain Credentials Directories"
+references = ["https://objective-see.com/blog/blog_0x25.html"]
+risk_score = 73
+rule_id = "96e90768-c3b7-4df6-b5d9-6237f8bc36a8"
+severity = "high"
+tags = ["Elastic", "MacOS"]
+type = "query"
+
+query = '''
+event.category:process and event.type:(start or process_started) and
+  process.name:(zip or tar or gzip or 7za or hdiutil) and
+  process.args:("/Library/Keychains/" or "/Network/Library/Keychains/" or "~/Library/Keychains/")
+'''
+
+
+[[rule.threat]]
+framework = "MITRE ATT&CK"
+[[rule.threat.technique]]
+id = "T1142"
+name = "Keychain"
+reference = "https://attack.mitre.org/techniques/T1142/"
+
+
+[rule.threat.tactic]
+id = "TA0006"
+name = "Credential Access"
+reference = "https://attack.mitre.org/tactics/TA0006/"