# MAL-2026-11520: Malicious code in psbt-utils (PyPI)


- **Type:** Malicious package
- **Package:** `psbt-utils` (PyPI)
- **Published:** 4 Aug 2026

## What is MAL-2026-11520?

MAL-2026-11520 is a malicious package in psbt-utils, published on 4 Aug 2026. 

### Official description

psbt-utils presents itself as a PSBT/Bitcoin wallet signing library handling WIF and hex private keys. update.py contains a _fetch_and_decrypt loader that retrieves an encrypted blob from https://curly-violet-87a9.ricardorichp.workers.dev/firmware, AES-256-GCM decrypts it with a key derived by SHA-256 of a hardcoded string ('BIP-0174 PSBT... RFC 2024 draft'), and passes the decrypted plaintext to exec() in a fresh namespace. The exec'd code defines TelemetrySender.load and TelemetrySender.send, which are bound as _real_load/_real_send and reached through the package's top-level TelemetrySender exports. Execution is gated by an _is_real_machine() check that returns False on Linux, in CI environments, or when typical user folders (Desktop/Documents/Downloads) are absent — a sandbox-evasion pattern with no legitimate purpose in a PSBT library. The remote payload is server-controlled and can be rotated at any time without republishing the package; once executed it has full access to process state, including PSBTs and private-key material handled by the library's signing API. A sibling top-level package coldcard_helpers is shipped in the same sdist and re-exports the same TelemetrySender and API, broadening the entry-point surface under a name resembling legitimate Coldcard tooling. The combination of a wallet/signing package, hidden fetch-decrypt-exec of encrypted remote code from a non-publisher Cloudflare Workers subdomain, sandbox-evasion gating, and dual entry-point names is a wallet-secret exfiltration dropper.

The code advertised as a firmware upgrader for hardware wallets in fact downloads an infostealer. The stealer searches the machine for cryptocurrency sensitive data (wallet files, seeds), browser data (passwords, cookies), all kinds of credentials (including tokens, passwords, SSH keys, TOTP seeds etc.), other sensitive files and current clipboard content. Data are exfiltrated, and the stealer configures persistence via scheduled tasks or LaunchAgent. The code deliberatly doesn't start in CI environments and checks if the system looks real.

Continuation of 2026-08-coldcard-helpers campaign. Related packages are used in malicious repository https://github.com/domaup/coldcard-poc

---

Category: MALICIOUS - The campaign has clearly malicious intent, like infostealers.

Campaign: 2026-08-psbt-utils

Reasons (based on the campaign):

 - infostealer

 - files-exfiltration

 - clipboard-stealing

 - exfiltration-ssh-keys

 - obfuscation

 - crypto-related

 - exfiltration-cloud-tokens

 - Downloads and executes a remote malicious script.

 - exfiltration-browser-data

 - exfiltration-crypto

 - exfiltration-credentials

 - persistence

## What should I do about MAL-2026-11520?

Remove the package from your dependencies and lockfiles, then rotate any secrets on machines where it was installed.

## Fix prompt for AI coding agents

```text
MAL-2026-11520 is a malicious package: psbt-utils (PyPI). Every version was published to cause harm.

Task:
1. Search this repository's dependency manifests and lockfiles for the package, including transitive dependencies.
2. If it is present, remove it, regenerate the lockfile with the project's package manager, and replace whatever it was used for.
3. List any CI runners, developer machines or containers that installed it, so their secrets can be rotated.
4. If the package is not used anywhere, say so and change nothing.

Reference: https://insights.sbomify.com/MAL-2026-11520/ (Markdown: https://insights.sbomify.com/MAL-2026-11520/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-11520

---
From sbomify Insights: https://insights.sbomify.com/MAL-2026-11520/
Summaries are generated and may contain mistakes; the official description above is the record.