Which versions of base62-86x are malicious?

The following npm versions of base62-86x are flagged malicious: 5.0.4, 5.0.5. Treat any of these as compromised.

How do I remediate base62-86x if I installed it?

base62-86x is built to steal secrets, so assume every credential the build or runtime could read is compromised. Remove it from your project and lockfile, then rotate ALL exposed secrets — npm/registry tokens, cloud keys, CI/CD secrets, SSH keys, and any .env values — from a known-clean machine. Audit logs for unauthorized use of those credentials.

I already installed base62-86x — how do I know if it already compromised me?

If base62-86x was ever installed, its post-install/runtime payload may have already executed. O3's L7 egress monitoring and runtime eBPF sensors detect the credential exfiltration or command-and-control callback after install and block the malicious outbound channel, so you catch and contain the actual compromise — not just the presence of the package.

Is base62-86x part of a known attack campaign?

Yes — base62-86x is associated with the IN-MAL-2026-007489, IN-MAL-2026-007490 campaign. Packages in the same campaign often share infrastructure and payloads, so check whether any related packages are also in your dependency tree.

How do I find base62-86x across my projects, lockfiles, and CI pipelines?

Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for base62-86x (2 malicious versions). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging base62-86x across your stack and pipelines.

Malicious package

base62-86xnpm

Malicious code in base62-86x (npm) Remove it immediately and rotate any exposed credentials.

MAL-2026-6446

Immediate action

Remove the package, then rotate any secrets the build/runtime could reach.

npm uninstall base62-86x

What this malware does

Package impersonates the legitimate base-x/base62 library by Daniel Cousens (name base62-86x, homepage pointing at cryptocoinjs/base-x, identical source layout). The exported decode(string) function in both the CJS build (src/cjs/index.cjs) and the ESM build (src/esm/index.js) has been patched to silently POST every caller-supplied input to a hardcoded Telegram Bot API endpoint. The CJS variant hides the destination behind obfuscator.io string-array rotation that resolves to https://api.telegram.org/bot7837266935:<redacted>/sendMessage with chat_id 7974622428; the ESM variant wraps the same exfiltration in a custom bytecode VM whose base64 constant pool decodes to https://api.telegram.org/bot8880020840:<redacted>/sendMessage with chat_id 7959381237. Because consumers of a base-encoding library typically pass cryptocurrency addresses, private keys, identifiers, and other base-encoded secrets to decode(), every such call leaks the plaintext input to the attacker. Two distinct bot tokens indicate staged campaign or failover infrastructure. Heavy obfuscation of both bodies confirms intent to conceal the relay; there is no opt-in or documented behavior covering this network egress.

Malicious versions

2 flagged

5.0.45.0.5

Indicators of compromise (SHA-256)

811002816e7f72588c7c6540b088af5c44b8280574e43dbaeef4701fe377fe9f

e17ee17b7551bd21a24e7f07ca8cb8251b1725ae8dcd4dc29ecd6608589212a4

Detection & response playbook

Credential / info stealer

Find it
Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for base62-86x (2 malicious versions). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging base62-86x across your stack and pipelines.
If you installed it — respond
base62-86x is built to steal secrets, so assume every credential the build or runtime could read is compromised. Remove it from your project and lockfile, then rotate ALL exposed secrets — npm/registry tokens, cloud keys, CI/CD secrets, SSH keys, and any .env values — from a known-clean machine. Audit logs for unauthorized use of those credentials.
Did it already run?
If base62-86x was ever installed, its post-install/runtime payload may have already executed. O3's L7 egress monitoring and runtime eBPF sensors detect the credential exfiltration or command-and-control callback after install and block the malicious outbound channel, so you catch and contain the actual compromise — not just the presence of the package.
How O3 protects you
O3 blocks base62-86x before install through its supply-chain scanner, and if it has already run, detects and severs the exfiltration or C2 callback at runtime through L7 egress monitoring and eBPF.

Frequently asked questions

No. base62-86x on npm has been identified as a malicious package (versions 5.0.4, 5.0.5 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

IN-MAL-2026-007489IN-MAL-2026-007490

References

Credits

Amazon Inspector · finder

Detect & block this

O3 blocks base62-86x-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the credential exfiltration and severs the channel.

Malware detection Runtime egress monitoring