Populate rules/ directory.

Co-Authored-By: Brent Murphy <56412096+bm11100@users.noreply.github.com>
Co-Authored-By: Craig Chamberlain <randomuserid@users.noreply.github.com>
Co-Authored-By: David French <56409778+threat-punter@users.noreply.github.com>
Co-Authored-By: Derek Ditch <dcode@users.noreply.github.com>
Co-Authored-By: Justin Ibarra <brokensound77@users.noreply.github.com>

rules/linux/discovery_kernel_module_enumeration.toml

@@ -0,0 +1,47 @@
+[metadata]
+creation_date = "2020/04/23"
+ecs_version = ["1.4.0"]
+maturity = "production"
+updated_date = "2020/04/23"
+
+[rule]
+author = ["Elastic"]
+description = """
+Loadable Kernel Modules (or LKMs) are pieces of code that can be loaded and unloaded into the kernel upon demand. They
+extend the functionality of the kernel without the need to reboot the system. This identifies attempts to enumerate
+information about a kernel module.
+"""
+false_positives = [
+    """
+    Security tools and device drivers may run these programs in order to enumerate kernel modules. Use of these programs
+    by ordinary users is uncommon. These can be exempted by process name or username.
+    """,
+]
+index = ["auditbeat-*"]
+language = "kuery"
+license = "Elastic License"
+name = "Enumeration of Kernel Modules"
+risk_score = 47
+rule_id = "2d8043ed-5bda-4caf-801c-c1feb7410504"
+severity = "medium"
+tags = ["Elastic", "Linux"]
+type = "query"
+
+query = '''
+event.action:executed and process.args:(kmod and list and sudo or sudo and (depmod or lsmod or modinfo))
+'''
+
+
+[[rule.threat]]
+framework = "MITRE ATT&CK"
+[[rule.threat.technique]]
+id = "T1082"
+name = "System Information Discovery"
+reference = "https://attack.mitre.org/techniques/T1082/"
+
+
+[rule.threat.tactic]
+id = "TA0007"
+name = "Discovery"
+reference = "https://attack.mitre.org/tactics/TA0007/"
+