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rules: add runc to known_memfd_execution_binaries #268

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Merged
poiana merged 1 commit into from
Feb 17, 2025
Merged

rules: add runc to known_memfd_execution_binaries #268

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9 changes: 7 additions & 2 deletions rules/falco_rules.yaml
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Original file line number Diff line number Diff line change
Expand Up @@ -1230,10 +1230,15 @@
tags: [maturity_stable, host, container, network, process, mitre_execution, T1059]

- list: known_memfd_execution_binaries
items: []
items: [runc]

- macro: known_memfd_execution_processes
condition: (proc.name in (known_memfd_execution_binaries))
condition: >
(proc.name in (known_memfd_execution_binaries))
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@loresuso loresuso Feb 7, 2025

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Hi there! thanks for opening the PR.
I am not sure though this will work since:

  • when we execute from memfd, usually we use the proc filesystem reference to the fd to do so. The process name will be a numeric value such as "3"
  • IIRC, Falco doesn't resolve exepath and exe that way
    Possibly, the best option would be to tune the rule by using ancestors information, such as proc.pname and proc.aname

or (proc.pname in (known_memfd_execution_binaries))
or (proc.exepath = "memfd:runc_cloned:/proc/self/exe")
or (proc.exe = "memfd:runc_cloned:/proc/self/exe")


- rule: Fileless execution via memfd_create
desc: >
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