Dynamic Linker Creation or Modification

Last updated 25 days ago on 2025-09-29
Created a year ago on 2024-08-08

About

Detects the creation or modification of files related to the configuration of the dynamic linker on Linux systems. The dynamic linker is a shared library that is used by the Linux kernel to load and execute programs. Attackers may attempt to hijack the execution flow of a program by modifying the dynamic linker configuration files. This technique is often observed by userland rootkits that leverage shared objects to maintain persistence on a compromised host.
Tags
Domain: EndpointOS: LinuxUse Case: Threat DetectionTactic: Defense EvasionTactic: PersistenceData Source: Elastic DefendLanguage: eql
Severity
medium
Risk Score
47
MITRE ATT&CK™

Defense Evasion (TA0005)(opens in a new tab or window)

Persistence (TA0003)(opens in a new tab or window)

License
Elastic License v2(opens in a new tab or window)

Definition

Rule Type
Event Correlation Rule
Integration Pack
Prebuilt Security Detection Rules
Index Patterns
logs-endpoint.events.file*
Related Integrations

endpoint(opens in a new tab or window)

Query
file where host.os.type == "linux" and event.action in ("creation", "rename") and
file.path : ("/etc/ld.so.preload", "/etc/ld.so.conf.d/*", "/etc/ld.so.conf") and
not (
  process.executable in (
    "/bin/dpkg", "/usr/bin/dpkg", "/bin/dockerd", "/usr/bin/dockerd", "/usr/sbin/dockerd", "/bin/microdnf",
    "/usr/bin/microdnf", "/bin/rpm", "/usr/bin/rpm", "/bin/snapd", "/usr/bin/snapd", "/bin/yum", "/usr/bin/yum",
    "/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/autossl_check", "/usr/bin/autossl_check", "/proc/self/exe",  "/usr/bin/pamac-daemon",
    "/bin/pamac-daemon", "/usr/lib/snapd/snapd", "/usr/local/bin/dockerd", "/usr/libexec/platform-python",
    "/usr/lib/snapd/snap-update-ns", "/usr/bin/vmware-config-tools.pl", "./usr/bin/podman", "/bin/nvidia-cdi-hook",
    "/usr/lib/dracut/dracut-install", "./usr/bin/nvidia-cdi-hook", "/.envbuilder/bin/envbuilder", "/usr/bin/buildah",
    "/usr/sbin/dnf", "/usr/bin/pamac", "/sbin/pacman", "/usr/bin/crio", "/usr/sbin/yum-cron"
  ) or
  file.extension in ("swp", "swpx", "swx", "dpkg-remove") or
  file.Ext.original.extension == "dpkg-new" or
  process.executable : (
    "/nix/store/*", "/var/lib/dpkg/*", "/snap/*", "/dev/fd/*", "/usr/lib/virtualbox/*", "/opt/dynatrace/oneagent/*",
    "/usr/libexec/platform-python*"
  ) or
  process.executable == null or
  process.name in (
    "java", "executor", "ssm-agent-worker", "packagekitd", "crio", "dockerd-entrypoint.sh",
    "docker-init", "BootTimeChecker", "dockerd (deleted)", "dockerd"
  ) or
  (process.name == "sed" and file.name : "sed*") or
  (process.name == "perl" and file.name : "e2scrub_all.tmp*") or
  (process.name == "init" and file.name == "ld.wsl.conf") or
  (process.name == "sshd" and file.extension == "dpkg-new")
)

Install detection rules in Elastic Security

Detect Dynamic Linker Creation or Modification in the Elastic Security detection engine by installing this rule into your Elastic Stack.

To setup this rule, check out the installation guide for Prebuilt Security Detection Rules(opens in a new tab or window).