Avoid running tests / local serves directly on this machine (for now)

Date: 2026-06-25 Updated: 2026-08-25 (issue #8919) Scope: the Windows dev box this repo is checked out on (C:\work\fak), not CI, WSL, or the GPU nodes.

Superseded diagnosis: The August 25, 2026 audit for issue #8919 supersedes this note’s earlier attribution to Windows Application Control. Current Windows event evidence identifies Microsoft Defender Antivirus real-time ML detections and quarantines of transient Go test executables instead.

The rule

Do not run the test suite or stand up a local fak serve directly on this Windows machine right now. Two reasons, one hard and one operational:

1. Native go test is repeatedly disrupted here by Defender Antivirus. The Defender Operational event log records 78 detections covering 57 unique binaries from July 26 through August 8, 2026. Recorded threat-family labels include Wacatac, Wacapew, Sabsik, and Bearfoos. Go creates fresh transient test executables, so a new binary identity is scanned and can trigger the same detection and quarantine behavior again; retrying with a fresh build does not remove the cause. These labels and actions establish what Defender reported and did. They do not, by themselves, establish that the detections are false positives or that any binary is safe.

2. This box is a shared, busy multi-session tree. It also hosts the live dispatch fleet and unrelated workloads. Local fak serve / Vulkan-GGUF test processes left running here pile up; a single stray fak-vulkan-pressuretrim-latest serve was holding 4.3 GB with zero established connections when this note was written. They are leftover memory pressure.

What to do instead

• Tests: preserve the supported WSL path: run ./test.ps1 from the repo root under WSL, or let CI run them. For the fast gate, use the repository’s isolated build/validation verbs where applicable; do not treat a quarantined native Windows test executable as a test result.
• Do not weaken endpoint protection: do not disable Microsoft Defender Antivirus, turn off real-time protection, or add broad process, folder, repository, Go-cache, or temporary-directory exclusions. Escalate any narrowly scoped remediation through the machine’s security owner with the event evidence; this note does not declare the binaries safe.
• Local serve for a real model: use the GPU nodes / cloud serve (the in-kernel L4 fak-realmodel path), not a long-lived fak serve on this Windows box.
• If you must spin up a local serve to reproduce something: kill it when done. Verify with Get-NetTCPConnection -State Listen -LocalPort <port> and stop the owning PID.

Read-only Defender event diagnostic

This PowerShell command only reads the Defender Operational log. It does not change Defender settings, restore quarantined files, or create exclusions:

$start = [datetime]'2026-07-26T00:00:00'
$end = [datetime]'2026-08-09T00:00:00'
Get-WinEvent -FilterHashtable @{
  LogName = 'Microsoft-Windows-Windows Defender/Operational'
  Id = 1116, 1117
  StartTime = $start
  EndTime = $end
} | Select-Object TimeCreated, Id, ProviderName, Message

Event IDs 1116 and 1117 expose Defender detection and action records. Preserve the raw event output for diagnosis, but do not infer false-positive status or binary safety from family labels, filenames, counts, or quarantine actions alone.

Cleanup recipe (what was done on 2026-06-25)

Find stray local fak serves and idle big processes:

# Top memory holders
Get-Process | Sort-Object WorkingSet64 -Descending | Select-Object -First 20 Name, Id, @{N='WS_MB';E={[math]::Round($_.WorkingSet64/1MB,0)}}

# Local serves that nobody is connected to (safe to kill)
Get-CimInstance Win32_Process | Where-Object { $_.CommandLine -match 'fak.*serve' } |
  Select-Object ProcessId, CommandLine
Get-NetTCPConnection -State Established | Where-Object { $_.OwningProcess -eq <PID> }   # empty => idle => kill

Killed this pass: fak-vulkan-pressuretrim-latest serve (idle local Vulkan serve, ~4.3 GB), fak.exe serve --session-id human-try (idle dogfood serve, port 8080), and a hung 11-hour gcloud config list (~1 GB). Left the live dispatch fleet and the C:\work\job batch alone.