Malicious code in synago (PyPI)

---

__

Source: amazon-inspector (a3e1bae7957cb735edd8424c1d2efe54b597c3a484ba77c9239e9ff8ec06327f)

The package installs synago-setup.pth, which Python auto-executes on every interpreter startup (not only on import synago). The.pth contains an obfuscated single-line exec() string with single-letter import aliases (_o, _s, _u, _p, _y, _b, _j, _z, _zf) gated by a /tmp/.bun_ran sentinel so it runs only once per machine. On first run it fetches https://github.com/oven-sh/bun/releases/download/bun-v1.3.13/bun-{os}-{arch}.zip via urllib, unzips it to /tmp/b/bun, chmods the binary executable (mode 509 / 0o775), deletes the zip, and invokes subprocess.run([bun, 'run', _index.js]) against a JavaScript file shipped in the package. The package advertises itself as an LLM agent framework — there is no legitimate reason for it to install a .pth hook, fetch an alternate language runtime, stage it under /tmp, and execute bundled JavaScript at every Python invocation. The combination of .pth auto-execution (a vector that bypasses normal import sandboxes), obfuscated exec() of a quoted string, sentinel-based once-per-host gating to evade re-detonation, and an out-of-band runtime executing code that Python-only scanners will not inspect is the alternate-runtime dropper pattern. Installing this package causes arbitrary attacker-controlled JavaScript to execute on the installer's machine on every subsequent Python startup.

Source: kam193 (bee487bb185457ca9e9d74e0963e23be3e84241a6bcd7d0bd5ca44855dd7d28b)

Versions 0.1.1, 0.1.2 were compromised.

Compromised packages start an obfuscated infostealer. The infostealer is a heavily obfuscated JavaScript code executed using Bun runtime on Python startup. It collectes all kinds of sensitive data, including API keys, credentials to package repositories, cryptocurrency assets, password manager data. Infostealer actively queries online services to collect additional secrets as well as attempts to gain persistence and spread further by publishing infected packages using collected credentials. Data are exfiltrated likely using Github. The code seems to threaten to wipe the user's data if it detects invalid GitHub tokens. Cleanup should be done with caution.

It seems to be related to the recent Mini Shai Hulud campaign.

---

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

Campaign: 2026-06-compr-woodpecker

Reasons (based on the campaign):

• compromised-package

• exfiltration-env-variables

• exfiltration-cloud-tokens

• exfiltration-credentials

• abuses-pth

• obfuscation

• infostealer

• The package contains code to detect if it is running in a sandbox environment.

• exfiltration-crypto

• files-exfiltration

• destructive-actions