Dynamic Linker Copy

Detects the copying of the Linux dynamic loader binary and subsequent file creation for the purpose of creating a backup copy. This technique was seen recently being utilized by Linux malware prior to patching the dynamic loader in order to inject and preload a malicious shared object file. This activity should never occur and if it does then it should be considered highly suspicious or malicious.

Rule type: eql

Rule indices:

logs-*

Severity: high

Risk score: 85

Runs every: 5m

Searches indices from: now-9m (Date Math format, see also Additional look-back time)

Maximum alerts per execution: 100

References:

https://www.intezer.com/blog/incident-response/orbit-new-undetected-linux-threat/

Tags:

Elastic
Host
Linux
Threat Detection
Persistence
Orbit

Version: 3

Rule authors:

Elastic

Rule license: Elastic License v2

Rule query

edit

sequence by process.entity_id with maxspan=1m
[process where event.type == "start" and process.name : ("cp", "rsync") and process.args : ("/lib/x86_64-linux-gnu/ld-linux-x86-64.so.2", "/etc/ld.so.preload")]
[file where event.action == "creation" and file.extension == "so"]

Framework: MITRE ATT&CK^TM

Tactic:
- Name: Persistence
- ID: TA0003
- Reference URL: https://attack.mitre.org/tactics/TA0003/
Technique:
- Name: Hijack Execution Flow
- ID: T1574
- Reference URL: https://attack.mitre.org/techniques/T1574/
Sub-technique:
- Name: Dynamic Linker Hijacking
- ID: T1574.006
- Reference URL: https://attack.mitre.org/techniques/T1574/006/

« Chkconfig Service Add Suspicious File Creation in /etc for Persistence »