postboi@0.29.0
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AI Security Review
scanned 3mo ago · by lpm-firewall-aiThis is not concrete malware: installation has no malicious lifecycle hook and the flagged behavior is user-confirmed. It remains a warn-level explicit AI-agent capability/configuration mutation under the firewall policy.
Static reason
High-risk behavior combination matched malicious policy.
Trigger
User runs `postboi init` and accepts the agent-skill prompt.
Impact
Adds package-authored instructions that AI agents may follow in that project.
Mechanism
Prompt-gated project-local AI-agent skill installation.
AI rationale
This is not concrete malware: installation has no malicious lifecycle hook and the flagged behavior is user-confirmed. It remains a warn-level explicit AI-agent capability/configuration mutation under the firewall policy.
Evidence
package.jsondist/cli.jsskills/postboi/SKILL.md.claude/skills/postboi/SKILL.md
Network endpoints1
postboi.app
Decision evidence
public snapshotAI called this Suspicious at 88.0% confidence as Dangerous Capability with medium false-positive risk.
Evidence for warning
- `postboi init` offers to install a bundled agent skill at `.claude/skills/postboi/SKILL.md` and writes it after confirmation.
- The CLI dispatches this behavior only for the explicit `init` command.
Evidence against
- No preinstall, install, or postinstall hook; `prepare` only runs `svelte-kit sync`.
- The agent-skill write is prompt-gated, project-local, and no stealth, payload execution, or broad agent-config mutation was found.
- Environment reads and outbound requests support configured messaging providers and the authenticated Postboi service; no unrelated exfiltration path was found.
- Child-process use opens an authorization browser or runs explicitly approved hosting/package-manager commands.
Behavioral surface
ChildProcessCryptoDynamicRequireEnvironmentVarsFilesystemNetworkShell
HighEntropyStringsMinified
Source & flagged code
6 flaggeddist/cli.jsView file
108const { pathToFileURL } = await import("node:url");
L109: let dir = process.cwd();
L110: for (;; ) {
...
L245: if (this.#hooks.before?.send) {
L246: return this.#hooks.before.send({
L247: provider: this.provider,
...
L294: async send_request(url, init) {
L295: return fetch(url, init);
L296: }
...
L358: async read_json(response) {
L359: const text = await response.text();
L360: if (!text)
Critical
Credential Exfiltration
Source appears to send environment or credential material to an external endpoint.
dist/cli.jsView on unpkg · L108108const { pathToFileURL } = await import("node:url");
L109: let dir = process.cwd();
L110: for (;; ) {
...
L245: if (this.#hooks.before?.send) {
L246: return this.#hooks.before.send({
L247: provider: this.provider,
...
L294: async send_request(url, init) {
L295: return fetch(url, init);
L296: }
...
L358: async read_json(response) {
L359: const text = await response.text();
L360: if (!text)
Critical
Browser Credential Phishing
Source appears to collect browser login credentials for exfiltration.
dist/cli.jsView on unpkg · L108781import { readdirSync as readdirSync2, readFileSync as readFileSync4, writeFileSync as writeFileSync4, existsSync as existsSync3, appendFileSync } from "node:fs";
L782: import { spawnSync } from "node:child_process";
L783: import { join as join5, delimiter } from "node:path";
Findings
2 Critical3 High4 Medium6 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
LowNo License
Affected versions and remediation
This report applies to postboi@0.29.0.
See all versions of postboi for other recorded verdicts.
- Review the evidence and your use of postboi@0.29.0 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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