postboi@0.60.0
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 1mo ago · by lpm-firewall-aiSource supports a warning for explicit CLI agent configuration changes and subsequent instruction updates through package links. It does not establish malicious credential theft or unconsented npm install-time agent control mutation.
Static reason
High-risk behavior combination matched malicious policy.
Trigger
Running postboi skill or accepting skill setup during init; init --agent automatically accepts confirmations. Running sync refreshes an existing skill.
Impact
Agents may follow package-provided instructions that change with dependency upgrades, without a new setup confirmation.
Mechanism
Setup places skills under .claude and .agents, links them to installed package content, and appends a Postboi instruction pointer to AGENTS.md.
AI rationale
Source supports a warning for explicit CLI agent configuration changes and subsequent instruction updates through package links. It does not establish malicious credential theft or unconsented npm install-time agent control mutation.
Evidence
dist/cli.js.claude/skills/postboi/SKILL.md.agents/skills/postboi/SKILL.mdAGENTS.md
Decision evidence
public snapshotAI called this Suspicious at 94.0% confidence as Dangerous Capability with medium false-positive risk.
Evidence for warning
- package.json has a Svelte preparation hook, without an npm install hook invoking agent setup.
- The CLI offers confirmation before installing a new agent skill and appends a Postboi pointer to an existing AGENTS.md.
- Installed skills link to package content, so package upgrades can change the instructions agents read; the sync command refreshes existing skills.
- The explicit skill command activates agent setup.
- The init command's --agent mode uses automatic confirmations that default to acceptance.
Evidence against
- No concrete credential theft or browser credential harvesting was established; the inspected password input is disabled.
- The Microsoft 365 provider and poller authenticate through Microsoft's OAuth endpoint for Microsoft Graph.
- Agent configuration changes are activated by CLI commands rather than npm install hooks.
Behavioral surface
ChildProcessCryptoDynamicRequireEnvironmentVarsFilesystemNetwork
Source & flagged code
6 flaggeddist/cli.jsView file
41// src/library/encoding.ts
L42: function base64_decode(value) {
L43: const binary = atob(value);
...
L125: const { pathToFileURL } = await import("node:url");
L126: let dir = process.cwd();
L127: for (;; ) {
...
L270: if (this.#hooks.before?.send) {
L271: return this.#hooks.before.send({
L272: provider: this.provider,
...
L319: async send_request(url, init) {
L320: return fetch(url, init);
L321: }
Critical
Credential Exfiltration
Source appears to send environment or credential material to an external endpoint.
dist/cli.jsView on unpkg · L4141// src/library/encoding.ts
L42: function base64_decode(value) {
L43: const binary = atob(value);
...
L125: const { pathToFileURL } = await import("node:url");
L126: let dir = process.cwd();
L127: for (;; ) {
...
L270: if (this.#hooks.before?.send) {
L271: return this.#hooks.before.send({
L272: provider: this.provider,
...
L319: async send_request(url, init) {
L320: return fetch(url, init);
L321: }
Critical
Browser Credential Phishing
Source appears to collect browser login credentials for exfiltration.
dist/cli.jsView on unpkg · L41807} from "node:fs";
L808: import { spawnSync } from "node:child_process";
L809: import { join as join8, delimiter, dirname as dirname4 } from "node:path";
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@0.60.0.
See all versions of postboi for other recorded verdicts.
- Review the evidence and your use of postboi@0.60.0 before allowing it. Restrict the permissions described in this report.
- Choose an independently verified alternative or release. This report does not establish that other versions are safe.
Evidence last updated: .
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