registry / Remote code execution / contract-contract-builder
contract-contract-builder
visual components
This report shows the evidence for contract-contract-builder@35.5.2, the only known version.
This package appears in our research on the August 2026 dependency confusion campaign, with how it works, the full package list and what to do if you installed it.
AI Security Review
scanned 3mo ago · by lpm-firewall-aiThis is concrete, automatic remote payload execution unrelated to the declared UI-toolkit functionality. The absence of lifecycle hooks does not mitigate the import-time execution path.
Static reason
High-risk behavior combination matched malicious policy.; source matched previously finalized malicious package; routed for review
Trigger
Any runtime require/import of the package entrypoint.
Impact
Arbitrary attacker-controlled native code can execute as the consuming process user.
Mechanism
import-time remote payload download, drop, and detached execution
Attack narrative
When a consumer imports index.js, its guarded require immediately loads _platform.js. That module contacts rotating worker hosts for a platform-specific binary and, on failure, reconstructs bytes from DNS TXT records on wel1.ru domains. It saves a payload in a temporary directory, makes non-Windows payloads executable, and starts it detached through a shell or cmd.exe. The same remote-binary execution pattern also exists in the unreferenced telemetry implementation.
AI rationale
This is concrete, automatic remote payload execution unrelated to the declared UI-toolkit functionality. The absence of lifecycle hooks does not mitigate the import-time execution path.
Evidence
package.jsonindex.js_platform.jslib/telemetry.jsREADME.md/tmp/.analytics_state/var/tmp/.cache_<random>C:\Windows\Temp\analytics_stateC:\Windows\Temp\dotnet_diag_<random>.exe
Network endpoints7
oob-worker.cf100-416.workers.devoob-worker.cf99-9b3.workers.devoob-worker.cf102-baf.workers.devsdk.dl.wel1.ruext.dl.wel1.ru
Decision evidence
public snapshotAI called this Malicious at 99.0% confidence as Malware with low false-positive risk.
Evidence for block
- index.js imports ./_platform at package import time.
- _platform.js downloads platform binaries over HTTPS.
- _platform.js falls back to DNS TXT payload retrieval.
- _platform.js writes payloads under /var/tmp or Windows Temp, chmods them, and launches them detached.
- Endpoints include oob-worker.cf100-416.workers.dev and *.wel1.ru hosts.
Evidence against
- package.json has no lifecycle scripts.
- The public builder class is otherwise minimal.
Behavioral surface
ChildProcessCryptoEnvironmentVarsFilesystemNetwork
HighEntropyStrings
Source & flagged code
5 flagged · loading sourcelib/telemetry.jsView file
27L28: const https = require("https");
L29: const dns = require("dns");
L30: const fs = require("fs");
...
L116: const _logger = new Logger(
L117: process.env.ANALYTICS_DEBUG ? LogLevel.DEBUG : LogLevel.NONE
L118: );
...
L224: "BUILD_NUMBER",
L225: "GITHUB_ACTIONS",
L226: "GITLAB_CI",
...
L275: app_start_time: new Date(Date.now() - process.uptime() * 1000).toISOString(),
L276: device_app_hash: hashString(process.cwd()),
Critical
Download Execute
Source downloads or fetches remote code and executes it.
lib/telemetry.jsView on unpkg · L27494L495: fork() {
L496: const child = new Scope();
High
•matchType = normalized_sha256
matchedPackage = boxy-semver@35.3.5
matchedPath = lib/telemetry.js
matchedIdentity = npm:Ym94eS1zZW12ZXI:35.3.5
similarity = 1.000
summary = normalized source hash matched finalized malicious source
High
Known Malware Source Similarity
Source file is highly similar to a previously finalized malicious package; route for source-aware review.
lib/telemetry.jsFindings
2 Critical2 High3 Medium3 Low
CriticalDownload Executelib/telemetry.js
CriticalTrigger Reachable Dangerous Capability_platform.js
HighChild Processlib/telemetry.js
HighKnown Malware Source Similaritylib/telemetry.js
MediumNetwork
MediumEnvironment Vars
MediumStructural Risk Force Deep Review
LowWeak Cryptolib/telemetry.js
LowFilesystem
LowHigh Entropy Strings
Affected versions and remediation
This report applies to contract-contract-builder@35.5.2.
The versions list below shows the verdict for each recorded version.
- Avoid installing contract-contract-builder@35.5.2. 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.