Elastic Security Detection Rules

Suspicious Dynamic Linker Discovery via od

Last updated 5 months ago on 2025-03-20
Created 2 years ago on 2024-02-01

About

Monitors for dynamic linker discovery via the od utility. od (octal dump) is a command-line utility in Unix operating systems used for displaying data in various formats, including octal, hexadecimal, decimal, and ASCII, primarily used for examining and debugging binary files or data streams. Attackers can leverage od to analyze the dynamic linker by identifying injection points and craft exploits based on the observed behaviors and structures within these files.
Tags
Domain: EndpointOS: LinuxUse Case: Threat DetectionTactic: DiscoveryData Source: Elastic DefendData Source: Elastic EndgameData Source: Auditd ManagerData Source: CrowdstrikeData Source: SentinelOneLanguage: eql
Severity
low
Risk Score
21
MITRE ATT&CK™

Discovery (TA0007)(opens in a new tab or window)

↳ Process Discovery (T1057)(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
auditbeat-*endgame-*logs-auditd_manager.auditd-*logs-crowdstrike.fdr*logs-endpoint.events.process*logs-sentinel_one_cloud_funnel.*
Related Integrations

endpoint(opens in a new tab or window)

auditd_manager(opens in a new tab or window)

crowdstrike(opens in a new tab or window)

sentinel_one_cloud_funnel(opens in a new tab or window)

Query
process where host.os.type == "linux" and event.type == "start" and event.action in ("exec", "exec_event", "start", "ProcessRollup2", "executed", "process_started")
 and process.name == "od" and process.args in (
  "/lib/x86_64-linux-gnu/ld-linux-x86-64.so.2", "/etc/ld.so.preload", "/lib64/ld-linux-x86-64.so.2",
  "/usr/lib/x86_64-linux-gnu/ld-linux-x86-64.so.2", "/usr/lib64/ld-linux-x86-64.so.2"
)

Install detection rules in Elastic Security

Detect Suspicious Dynamic Linker Discovery via od 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).