Windows: Kaspersky blocks codex-command-runner 0.154.0 as PDM:Exploit.Win32.Generic.nblk

What version of Codex CLI is running?

0.154.0

What subscription do you have?

ChatGPT Pro

Which model were you using?

N/A — the issue affects the native Windows command runner and is not model-specific.

What platform is your computer?

Windows 11 Home 25H2, OS Build 26200.9445, x64

What terminal emulator and version are you using (if applicable)?

Windows Terminal / PowerShell

Codex doctor report

not available — I intentionally did not run additional Codex diagnostics because Kaspersky is currently blocking codex-command-runner-0.154.0.exe and I am avoiding additional native runner executions while the detection is under investigation.

What issue are you seeing?

Kaspersky Plus System Watcher is blocking the native Windows Codex CLI command runner:

%USERPROFILE%\.codex\.sandbox-bin\codex-command-runner-0.154.0.exe

Detection:

PDM:Exploit.Win32.Generic.nblk

SHA-256:

A57CA8BEB786A05F36C97309E8A716610C70CED9946DC1437BBBAF4566C0C403

File size:

8,218,416 bytes

I independently compared this sandbox copy with the command runner distributed by my installed official @openai/codex-win32-x64 npm package:

@openai/codex-win32-x64\vendor\x86_64-pc-windows-msvc\codex-resources\codex-command-runner.exe

Both files have the exact same SHA-256 and exact same file size.

Kaspersky Threat Intelligence Portal identifies the binary as signed by OpenAI OpCo, LLC.

There is also a conflicting result from Kaspersky itself:

• the reputation/lookup result for this exact SHA-256 reported Malware;
• local Kaspersky System Watcher blocks it as PDM:Exploit.Win32.Generic.nblk;
• but after I submitted the exact binary for Kaspersky dynamic analysis, the same SHA-256 was reported as Clean, with:
  • 0 malware detections
  • 0 suspicious activities
  • 0 network activities

I have submitted the binary to Kaspersky for reanalysis.

I have NOT disabled Kaspersky and have NOT added the binary or .codex directory to antivirus exclusions.

OpenAI Support advised me to file this issue so the Codex team can track the behavior.

What steps can reproduce the bug?

1. Install/use Codex CLI 0.154.0 on Windows 11 with Kaspersky Plus active.

2. Run Codex natively on Windows.

3. Let Codex execute a command that uses its native Windows sandbox command runner.

4. Kaspersky System Watcher detects/blocks:

   %USERPROFILE%\.codex\.sandbox-bin\codex-command-runner-0.154.0.exe

   as:

   PDM:Exploit.Win32.Generic.nblk

5. The Codex command/tool execution can then be interrupted or fail because the runner process is blocked.

The affected binary has SHA-256:

A57CA8BEB786A05F36C97309E8A716610C70CED9946DC1437BBBAF4566C0C403

What is the expected behavior?

The official Codex Windows command runner should be able to execute through the normal native Windows sandbox path without being blocked by endpoint protection as generic exploit/trojan behavior.

If this is a known antivirus false positive, I would expect either:

• the Codex/Kaspersky detection to be corrected upstream, or
• documented guidance for a safe native-Windows workaround that does not require broadly excluding the .codex directory from antivirus protection.

Additional information

Kaspersky evidence

For the same SHA-256:

A57CA8BEB786A05F36C97309E8A716610C70CED9946DC1437BBBAF4566C0C403

I observed:

• Local Kaspersky System Watcher:
  PDM:Exploit.Win32.Generic.nblk

• Kaspersky OpenTIP reputation result:
  Malware

  Detection names included generic entries such as:

  • BSS:Exploit.Win32.Generic
  • BSS:Exploit.Win32.Generic.nblk
  • BSS:Trojan.Win32.Generic
  • BSS:Trojan.Win32.Generic.nblk

• Subsequent Kaspersky dynamic analysis of the exact file:
  Clean

  • 0 malware detections
  • 0 suspicious activities
  • 0 network activities

The portal identifies the binary as signed by OpenAI OpCo, LLC.

Package provenance

The .codex\.sandbox-bin copy and the codex-command-runner.exe bundled in my installed official @openai/codex-win32-x64 package are byte-for-byte identical according to SHA-256 and file size.

I am not claiming that the published SHA-256 is officially documented by OpenAI; this is a local comparison between the installed package binary and the sandbox copy.

Support / vendor status

• I contacted OpenAI Support. Support could not confirm the hash from a published hash list and recommended filing this Codex issue.
• I submitted the exact file to Kaspersky for reanalysis.
• I have not disabled antivirus protection or added an exclusion.

Related reports

I found other Windows antivirus false-positive reports involving Codex, but did not find an exact duplicate for this native Codex CLI 0.154.0 command-runner / Kaspersky PDM detection.

Start by reproducing the block on Windows 11 with Kaspersky Plus and compare the SHA-256 of the .codex sandbox binary with the bundled @openai/codex-win32-x64 runner. Review the reported Kaspersky reputation and dynamic-analysis results. Done means the false positive is corrected upstream or a safe native-Windows workaround is documented without broadly excluding .codex.