Quarantine deletes a file from where its owner put it. Until now every
detection did that, so every false positive was destructive rather than
merely wrong — which on this machine cost an 8.5 MB compiler cache and a
4.3 MB session transcript, the latter's history permanently.
Each rule now declares what Hound may do:
action = "quarantine" move it to the vault
action = "alert" report it, leave it alone
**The default is alert**, and so is an unrecognised value, and so is a
detection name the engine does not know. One misspelt "quarantne" must
not turn an advisory rule into a destructive one across every machine
that updates.
Quarantine has to be earned by an ANCHOR, not by the author's
confidence:
EICAR-Test-Signature quarantine exact 68-byte payload, size-bounded
Linux.Coinminer.XMRig quarantine ELF magic
Linux.Rootkit.Preload quarantine ELF magic
Linux.Webshell.PHP-Eval ALERT content-only — PHP has no file
magic, so it can still match a
security write-up, a log or an AI
transcript quoting a webshell
A test asserts that property directly: any rule declaring quarantine
must contain a file-type check or an exact size bound. A future rule
cannot quietly claim the destructive action without one.
Both the execution gate and the inotify fallback consult it, kept in
step deliberately — a fallback more destructive than the primary path is
a trap for whoever ends up running unprivileged.
Verified live on the gated filesystem: a webshell written to disk is
reported and left in place; an ELF miner written beside it is
quarantined. Event text changed to match — "threat detected in X —
reported, not moved" rather than implying something happened.
One process note. The first attempt at this edit silently did nothing:
the replacement did not match because of indentation, the tooling
reported success, and the webshell was still moved. Second time I made
the edit assert its anchor before applying. That is the third silent
no-op edit in this session and the pattern is now obvious enough to
stop assuming an edit landed.
303 tests pass. Gate off.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
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