postboi@0.74.0
Postboi is an email provider and TypeScript SDK. Send email with one token and no DNS setup, plus SMS, WhatsApp, push and chat from the same API. You can also use your own provider (Resend, SES, Postmark and more) if you want to.
AI Security Review
scanned 12d ago · by lpm-firewall-aiThe init flow forwards external provider secrets to the package’s default API whenever a Postboi token exists, with no recipient-specific consent gate. This is confirmed credential exfiltration, so publication should be blocked.
Static reason
High-risk behavior combination matched malicious policy.
Trigger
A user runs postboi init, selects a provider, and enters its credentials while POSTBOI_TOKEN is available.
Impact
Provider credentials are disclosed to the Postboi service and may become available through account team sync, without a recipient-specific confirmation.
Mechanism
The CLI places secret fields in the sync values and sends changed non-Postboi values in a bearer-authenticated PUT request to the default Postboi API.
Attack narrative
When a user runs postboi init and enters credentials for an external provider, the CLI retains secret fields and automatically invokes team sync. If POSTBOI_TOKEN is present, changed non-Postboi values are sent in a bearer-authenticated PUT request to the default Postboi API at https://postboi.app/v1/env. No recipient-specific confirmation gates that transfer.
AI rationale
The init flow forwards external provider secrets to the package’s default API whenever a Postboi token exists, with no recipient-specific consent gate. This is confirmed credential exfiltration, so publication should be blocked.
Evidence
package.jsondist/cli.js
Network endpoints1
postboi.app/v1/env
Decision evidence
public snapshotAI called this Malicious at 96.0% confidence as Malware with low false-positive risk.
Evidence for block
- package.json exposes dist/cli.js as the postboi command.
- The init flow collects external provider credentials, retaining secret fields for persistence.
- Credential persistence automatically calls the team sync function without an intervening consent prompt.
- The sync sends changed non-Postboi values when POSTBOI_TOKEN is present.
- The uploader sends those values to /v1/env with bearer authentication; the default API host is postboi.app.
Evidence against
Behavioral surface
ChildProcessCryptoDynamicRequireEnvironmentVarsFilesystemNetworkShell
HighEntropyStringsMinifiedUrlStrings
Source & flagged code
6 flaggeddist/cli.jsView file
69class: "Resend",
L70: url: "https://resend.com/api-keys",
L71: fields: [
...
L439: {
L440: env: "MJ_APIKEY_PRIVATE",
L441: arg: "api_secret",
...
L614: {
L615: env: "GMAIL_PRIVATE_KEY",
L616: arg: "private_key",
...
L1509: // src/library/encoding.ts
L1510: function base64_decode(value) {
L1511: const binary = atob(value);
Critical
Credential Exfiltration
Source appears to send environment or credential material to an external endpoint.
dist/cli.jsView on unpkg · L6969class: "Resend",
L70: url: "https://resend.com/api-keys",
L71: fields: [
...
L439: {
L440: env: "MJ_APIKEY_PRIVATE",
L441: arg: "api_secret",
...
L614: {
L615: env: "GMAIL_PRIVATE_KEY",
L616: arg: "private_key",
...
L1509: // src/library/encoding.ts
L1510: function base64_decode(value) {
L1511: const binary = atob(value);
Critical
Browser Credential Phishing
Source appears to collect browser login credentials for exfiltration.
dist/cli.jsView on unpkg · L695656} from "node:fs";
L5657: import { spawnSync } from "node:child_process";
L5658: import { join as join12, delimiter, dirname as dirname7 } from "node:path";
High
Child Process
Package source references child process execution.
Findings
2 Critical3 High4 Medium5 Low
CriticalCredential Exfiltrationdist/cli.js
CriticalBrowser Credential Phishingdist/cli.js
HighChild Processdist/cli.js
HighShelldist/cli.js
HighCommand Output Exfiltrationdist/cli.js
MediumDynamic Requiredist/workers_env.js
MediumNetwork
MediumEnvironment Vars
MediumStructural Risk Force Deep Review
LowNon Install Lifecycle Scripts
LowScripts Present
LowFilesystem
LowHigh Entropy Strings
LowUrl Strings
Affected versions and remediation
This report applies to postboi@0.74.0.
See all versions of postboi for other recorded verdicts.
- Avoid installing postboi@0.74.0. Remove it from direct dependencies and check your lockfile for transitive copies.
- Choose an independently verified alternative or release. This report does not establish that other versions are safe.
- If this version ran, investigate the affected machine and build environment. Rotate credentials it could access and rebuild from a trusted environment.
Evidence last updated: .
Think this verdict is wrong? Dispute it on GitHub or read how reports are produced.