[Rule Tuning] Q2 Linux DR Tuning - Part 5 (#4166)

* [Rule Tuning] Q2 Linux DR Tuning - Part 5

* Update persistence_suspicious_ssh_execution_xzbackdoor.toml

* Update persistence_rpm_package_installation_from_unusual_parent.toml

(cherry picked from commit b309bcb)

Author: Aegrah

rules/linux/persistence_setuid_setgid_capability_set.toml

@@ -2,7 +2,7 @@
 creation_date = "2023/09/05"
 integration = ["endpoint"]
 maturity = "production"
-updated_date = "2024/05/21"
+updated_date = "2024/10/17"
 
 [transform]
 [[transform.osquery]]
@@ -141,35 +141,36 @@ tags = [
 ]
 timestamp_override = "event.ingested"
 type = "eql"
-
 query = '''
 process where host.os.type == "linux" and event.type == "start" and event.action in ("exec", "exec_event") and 
-process.name == "setcap" and process.args : "cap_set?id+ep" and not process.parent.name in ("jem", "vzctl")
+process.name == "setcap" and process.args : "cap_set?id+ep" and not (
+  process.parent.name in ("jem", "vzctl") or
+  process.args like "/usr/bin/new?idmap"
+)
 '''
 
-
 [[rule.threat]]
 framework = "MITRE ATT&CK"
 
 [rule.threat.tactic]
 id = "TA0003"
 name = "Persistence"
 reference = "https://attack.mitre.org/tactics/TA0003/"
+
 [[rule.threat]]
 framework = "MITRE ATT&CK"
+
 [[rule.threat.technique]]
 id = "T1548"
 name = "Abuse Elevation Control Mechanism"
 reference = "https://attack.mitre.org/techniques/T1548/"
+
 [[rule.threat.technique.subtechnique]]
 id = "T1548.001"
 name = "Setuid and Setgid"
 reference = "https://attack.mitre.org/techniques/T1548/001/"
 
-
-
 [rule.threat.tactic]
 id = "TA0004"
 name = "Privilege Escalation"
 reference = "https://attack.mitre.org/tactics/TA0004/"
-

…ux/persistence_user_password_change.toml …ersistence_shadow_file_modification.tomlrules/linux/persistence_user_password_change.toml renamed to rules/linux/persistence_shadow_file_modification.toml rules/linux/persistence_user_password_change.toml renamed to rules/linux/persistence_shadow_file_modification.toml

@@ -2,7 +2,7 @@
 creation_date = "2024/07/05"
 integration = ["endpoint"]
 maturity = "production"
-updated_date = "2024/09/23"
+updated_date = "2024/10/17"
 
 [rule]
 author = ["Elastic"]
@@ -56,35 +56,33 @@ tags = [
 ]
 timestamp_override = "event.ingested"
 type = "eql"
-
 query = '''
 file where host.os.type == "linux" and event.type == "change" and event.action == "rename" and
 file.path == "/etc/shadow" and file.Ext.original.path != null
 '''
 
-
 [[rule.threat]]
 framework = "MITRE ATT&CK"
+
 [[rule.threat.technique]]
 id = "T1098"
 name = "Account Manipulation"
 reference = "https://attack.mitre.org/techniques/T1098/"
 
-
 [rule.threat.tactic]
 id = "TA0003"
 name = "Persistence"
 reference = "https://attack.mitre.org/tactics/TA0003/"
+
 [[rule.threat]]
 framework = "MITRE ATT&CK"
+
 [[rule.threat.technique]]
 id = "T1098"
 name = "Account Manipulation"
 reference = "https://attack.mitre.org/techniques/T1098/"
 
-
 [rule.threat.tactic]
 id = "TA0004"
 name = "Privilege Escalation"
 reference = "https://attack.mitre.org/tactics/TA0004/"
-

rules/linux/persistence_shared_object_creation.toml

@@ -2,7 +2,7 @@
 creation_date = "2023/06/09"
 integration = ["endpoint"]
 maturity = "production"
-updated_date = "2024/05/21"
+updated_date = "2024/10/17"
 
 [transform]
 [[transform.osquery]]
@@ -163,36 +163,39 @@ type = "new_terms"
 query = '''
 host.os.type:linux and event.action:(creation or file_create_event or file_rename_event or rename) and 
 file.path:(/dev/shm/* or /usr/lib/*) and file.extension:so and process.name:* and not (
-  process.name:("dockerd" or "dpkg" or "rpm" or "snapd" or "yum" or "vmis-launcher" or "pacman" or
-  "apt-get" or "dnf" or "podman" or "platform-python") or 
-  (process.name:vmware-install.pl and file.path:/usr/lib/vmware-tools/*)
+  process.name:(
+    "dockerd" or "dpkg" or "rpm" or "snapd" or "yum" or "vmis-launcher" or "pacman" or "apt-get" or "dnf" or "podman" or
+    platform-python* or "dnf-automatic" or "unattended-upgrade" or "apk" or "snap-update-ns" or "install" or "exe" or
+    "systemd" or "root" or "sshd" or "pip" or "jlink" or python* or "update-alternatives" or pip* or
+    "installer.bin.inst" or "uninstall-bin" or "linux_agent.inst"
+  ) or 
+  (process.name:vmware-install.pl and file.path:/usr/lib/vmware-tools/*) or
+  process.executable : (/dev/fd/* or "/" or "/kaniko/executor" or "/usr/bin/buildah")
 )
 '''
 
-
 [[rule.threat]]
 framework = "MITRE ATT&CK"
+
 [[rule.threat.technique]]
 id = "T1574"
 name = "Hijack Execution Flow"
 reference = "https://attack.mitre.org/techniques/T1574/"
+
 [[rule.threat.technique.subtechnique]]
 id = "T1574.006"
 name = "Dynamic Linker Hijacking"
 reference = "https://attack.mitre.org/techniques/T1574/006/"
 
-
-
 [rule.threat.tactic]
 id = "TA0003"
 name = "Persistence"
 reference = "https://attack.mitre.org/tactics/TA0003/"
 
 [rule.new_terms]
 field = "new_terms_fields"
-value = ["host.id", "file.path", "process.executable"]
+value = ["file.path", "process.executable"]
+
 [[rule.new_terms.history_window_start]]
 field = "history_window_start"
 value = "now-10d"
-
-

rules/linux/persistence_shell_configuration_modification.toml

@@ -2,7 +2,7 @@
 creation_date = "2024/04/30"
 integration = ["endpoint"]
 maturity = "production"
-updated_date = "2024/09/23"
+updated_date = "2024/10/17"
 
 [rule]
 author = ["Elastic"]
@@ -59,7 +59,6 @@ tags = [
 ]
 timestamp_override = "event.ingested"
 type = "eql"
-
 query = '''
 file where host.os.type == "linux" and event.action in ("rename", "creation") and file.path : (
   // system-wide configurations
@@ -94,27 +93,26 @@ file where host.os.type == "linux" and event.action in ("rename", "creation") an
     "/usr/libexec/platform-python*"
   ) or
   process.executable == null or
+  process.name in ("adclient", "mkhomedir_helper", "teleport", "mkhomedir", "adduser", "desktopDaemon") or
   (process.name == "sed" and file.name : "sed*") or
   (process.name == "perl" and file.name : "e2scrub_all.tmp*") 
 )
 '''
 
-
 [[rule.threat]]
 framework = "MITRE ATT&CK"
+
 [[rule.threat.technique]]
 id = "T1546"
 name = "Event Triggered Execution"
 reference = "https://attack.mitre.org/techniques/T1546/"
+
 [[rule.threat.technique.subtechnique]]
 id = "T1546.004"
 name = "Unix Shell Configuration Modification"
 reference = "https://attack.mitre.org/techniques/T1546/004/"
 
-
-
 [rule.threat.tactic]
 id = "TA0003"
 name = "Persistence"
 reference = "https://attack.mitre.org/tactics/TA0003/"
-

rules/linux/persistence_ssh_netcon.toml

@@ -2,7 +2,7 @@
 creation_date = "2024/06/06"
 integration = ["endpoint"]
 maturity = "production"
-updated_date = "2024/07/18"
+updated_date = "2024/10/17"
 
 [rule]
 author = ["Elastic"]
@@ -41,7 +41,10 @@ sequence by host.id with maxspan=1s
      "192.175.48.0/24","198.18.0.0/15", "198.51.100.0/24", "203.0.113.0/24", "240.0.0.0/4", "::1", "FE80::/10",
      "FF00::/8", "172.31.0.0/16"
      )
-    ) and not process.executable in ("/bin/yum", "/usr/bin/yum")
+    ) and not (
+      process.executable in ("/bin/yum", "/usr/bin/yum") or
+      process.name in ("login_duo", "ssh", "sshd", "sshd-session")
+    )
   ] by process.parent.entity_id
 '''
 

rules/linux/persistence_suspicious_ssh_execution_xzbackdoor.toml

@@ -2,7 +2,7 @@
 creation_date = "2024/04/01"
 integration = ["endpoint"]
 maturity = "production"
-updated_date = "2024/09/23"
+updated_date = "2024/10/17"
 
 [rule]
 author = ["Elastic"]
@@ -40,63 +40,65 @@ sequence by host.id, user.id with maxspan=1s
  [process where host.os.type == "linux" and event.type == "start" and event.action == "exec" and process.name == "sshd" and
     process.args == "-D" and process.args == "-R"] by process.pid, process.entity_id
  [process where host.os.type == "linux" and event.type == "start" and event.action == "exec" and process.parent.name == "sshd" and 
-  process.executable != null and 
-  not process.executable in ("/usr/sbin/sshd", "/usr/sbin/unix_chkpwd", "/usr/bin/google_authorized_keys", "/usr/bin/fipscheck") and 
-  process.command_line != "sh -c /usr/bin/env -i PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin run-parts --lsbsysinit /etc/update-motd.d > /run/motd.dynamic.new"] by process.parent.pid, process.parent.entity_id
+  process.executable != null and not (
+    process.executable in ("/usr/sbin/sshd", "/usr/sbin/unix_chkpwd", "/usr/bin/google_authorized_keys", "/usr/bin/fipscheck") or
+    process.args like ("rsync*", "systemctl*", "/usr/sbin/unix_chkpwd", "/usr/bin/google_authorized_keys", "/usr/sbin/aad_certhandler*") or
+    process.command_line like "sh -c /usr/bin/env -i PATH=*"
+  )] by process.parent.pid, process.parent.entity_id
  [process where host.os.type == "linux" and event.action == "end" and process.name == "sshd" and process.exit_code != 0] by process.pid, process.entity_id
  [network where host.os.type == "linux" and event.type == "end" and event.action == "disconnect_received" and process.name == "sshd"] by process.pid, process.entity_id
 '''
 
-
 [[rule.threat]]
 framework = "MITRE ATT&CK"
+
 [[rule.threat.technique]]
 id = "T1543"
 name = "Create or Modify System Process"
 reference = "https://attack.mitre.org/techniques/T1543/"
 
-
 [rule.threat.tactic]
 id = "TA0003"
 name = "Persistence"
 reference = "https://attack.mitre.org/tactics/TA0003/"
+
 [[rule.threat]]
 framework = "MITRE ATT&CK"
+
 [[rule.threat.technique]]
 id = "T1556"
 name = "Modify Authentication Process"
 reference = "https://attack.mitre.org/techniques/T1556/"
 
-
 [rule.threat.tactic]
 id = "TA0006"
 name = "Credential Access"
 reference = "https://attack.mitre.org/tactics/TA0006/"
+
 [[rule.threat]]
 framework = "MITRE ATT&CK"
+
 [[rule.threat.technique]]
 id = "T1021"
 name = "Remote Services"
 reference = "https://attack.mitre.org/techniques/T1021/"
+
 [[rule.threat.technique.subtechnique]]
 id = "T1021.004"
 name = "SSH"
 reference = "https://attack.mitre.org/techniques/T1021/004/"
 
-
 [[rule.threat.technique]]
 id = "T1563"
 name = "Remote Service Session Hijacking"
 reference = "https://attack.mitre.org/techniques/T1563/"
+
 [[rule.threat.technique.subtechnique]]
 id = "T1563.001"
 name = "SSH Hijacking"
 reference = "https://attack.mitre.org/techniques/T1563/001/"
 
-
-
 [rule.threat.tactic]
 id = "TA0008"
 name = "Lateral Movement"
 reference = "https://attack.mitre.org/tactics/TA0008/"
-

rules/linux/persistence_systemd_generator_creation.toml

@@ -2,7 +2,7 @@
 creation_date = "2024/06/19"
 integration = ["endpoint"]
 maturity = "production"
-updated_date = "2024/09/23"
+updated_date = "2024/10/17"
 
 [rule]
 author = ["Elastic"]
@@ -60,7 +60,6 @@ tags = [
 ]
 timestamp_override = "event.ingested"
 type = "eql"
-
 query = '''
 file where host.os.type == "linux" and event.action in ("rename", "creation") and file.path : (
 "/run/systemd/system-generators/*", "/etc/systemd/system-generators/*",
@@ -75,49 +74,48 @@ file where host.os.type == "linux" and event.action in ("rename", "creation") an
     "/bin/dnf", "/usr/bin/dnf", "/bin/podman", "/usr/bin/podman", "/bin/dnf-automatic", "/usr/bin/dnf-automatic",
     "/bin/pacman", "/usr/bin/pacman", "/usr/bin/dpkg-divert", "/bin/dpkg-divert", "/sbin/apk", "/usr/sbin/apk",
     "/usr/local/sbin/apk", "/usr/bin/apt", "/usr/sbin/pacman", "/bin/podman", "/usr/bin/podman", "/usr/bin/puppet",
-    "/bin/puppet", "/opt/puppetlabs/puppet/bin/puppet", "/usr/bin/chef-client", "/bin/chef-client",
+    "/bin/puppet", "/opt/puppetlabs/puppet/bin/puppet", "/usr/bin/chef-client", "/bin/chef-client", "/usr/sbin/sshd",
     "/bin/autossl_check", "/usr/bin/autossl_check", "/proc/self/exe", "/dev/fd/*",  "/usr/bin/pamac-daemon",
-    "/bin/pamac-daemon", "/usr/lib/snapd/snapd", "/usr/local/bin/dockerd"
+    "/bin/pamac-daemon", "/usr/lib/snapd/snapd", "/usr/local/bin/dockerd", "/usr/libexec/platform-python"
   ) or
   file.extension in ("swp", "swpx", "swx", "dpkg-remove") or
   file.Ext.original.extension == "dpkg-new" or
   process.executable == null
 )
 '''
 
-
 [[rule.threat]]
 framework = "MITRE ATT&CK"
+
 [[rule.threat.technique]]
 id = "T1543"
 name = "Create or Modify System Process"
 reference = "https://attack.mitre.org/techniques/T1543/"
+
 [[rule.threat.technique.subtechnique]]
 id = "T1543.002"
 name = "Systemd Service"
 reference = "https://attack.mitre.org/techniques/T1543/002/"
 
-
-
 [rule.threat.tactic]
 id = "TA0003"
 name = "Persistence"
 reference = "https://attack.mitre.org/tactics/TA0003/"
+
 [[rule.threat]]
 framework = "MITRE ATT&CK"
+
 [[rule.threat.technique]]
 id = "T1543"
 name = "Create or Modify System Process"
 reference = "https://attack.mitre.org/techniques/T1543/"
+
 [[rule.threat.technique.subtechnique]]
 id = "T1543.002"
 name = "Systemd Service"
 reference = "https://attack.mitre.org/techniques/T1543/002/"
 
-
-
 [rule.threat.tactic]
 id = "TA0004"
 name = "Privilege Escalation"
 reference = "https://attack.mitre.org/tactics/TA0004/"
-