Like a lot of developers in this market, I’ve been taking freelance assessments and Discord job leads more seriously than I normally would.
One of those assessments turned into a malware investigation.
One day, I saw a post in a Discord server looking for a fullstack dev. I pitched. The reply looked routine at first: they DM’d me a requirements PDF for an assessment. I did not trust it, so I asked them to paste the requirements in the chat instead. They sent screenshots of the PDF, and it looked like a real assessment. Clean structure, clear expectations, nothing immediately screaming scam.
Then they invited me to a GitHub repo called E-commerce-template-12d46f3e. My first thought was that the name looked autogenerated, like they were appending random numbers for each assessment. That is when I started treating it like a security review, not a coding exercise.
The loader in lib/startupLogs.js:
- Walks through
public/flags/
- Reads each
.svg
- Extracts the text inside
<!-- ... -->
- Sorts and joins the fragments
- Base64-decodes the result
- Returns the decoded JavaScript
lib/serverStartup.jsfeeds that decoded string intoeval()
The two lines that made the whole thing click were basically this:
const dir = path.join(process.cwd(), setLogUrl("sxeolf2iodjv"));
eval(log_manager());
Part of the reconstructed payload after safely decoding the SVG fragments. I redacted active infrastructure details before publishing.
1. It fingerprints the machine
The payload gathers:
- local IPv4 addresses
- public IP via
api.ipify.org
- hostname
- OS type and version
- user info
- a machine/user identifier
- whether the machine looks virtualized
That means it profiles the environment before doing anything else.
2. It sends the profile to a remote server
It posts a JSON system profile to a remote endpoint over HTTP.
3. It drops and runs additional files on Windows
On Windows, it downloads executables into AppData and runs them.
It also writes a runjs.vbs file into the Windows Startup folder so the code can persist across reboots.
That is a classic persistence pattern.
4. It hunts for sensitive files
The script recursively scans user paths and drives for files matching patterns like:
.env.pem.key.cer.secret.txt.xlsxreadme.md.ssh.aws.github
That is collection logic, not a developer convenience feature.
5. It targets browser data
It looks for browser profile directories for:
- Chrome
- Brave
- Edge
- LT Browser
Then it checks for files such as:
Login DataWeb DataLocal Extension Settings
That is the kind of place malware checks when it wants tokens, cookies, or saved credentials.
6. It targets Sticky Notes
It also checks the Microsoft Sticky Notes storage path on Windows. That is another common place where people accidentally leave sensitive information.
Indicators
I am intentionally redacting the live infrastructure in the public draft.
- Redacted base URL:
[redacted-host]:[redacted-port]
- Observed endpoints:
/system-info/file-manage/download/track.js/download/apps/language_server_x64_x32_windows.exe/download/apps/assist_language_server_x64_x32_windows.exe
- Data sent to
/system-info:
- OS type, platform, release
- hostname
- user info
- local IP addresses
- public IP
- machine/user identifier
- VM detection flag
- Data uploaded to
/file-manage:
- file contents
- filename
- path
- system identifier
- File types and stores targeted locally:
.env,.pem,.key,.cer,.secret,.xlsx
- browser profile databases
- Microsoft Sticky Notes data
Why this was easy to miss
The repo looked like a regular Next.js storefront at a glance.
The package.json was mostly boring. The app structure looked normal. The assets looked like flags. The malicious code was buried in a runtime path that almost nobody checks unless they are being cautious on purpose.
That is the lesson here: malicious code does not have to live in node_modules, and it does not have to look obviously hostile. Sometimes it hides in the things you think are static content.
What I told myself while reviewing it
I kept repeating one rule: if a codebase wants to run something dynamically at startup, I need to know exactly why.
The moment I saw:
- an obfuscated loader
- base64 fragments hidden across image assets
eval()on decoded content- network calls to a hardcoded remote host
I stopped treating it like a normal assessment and started treating it like an incident.
What I would advise anyone else to do
If a Discord recruiter or random client sends you a repo:
- Check
package.jsonfirst, but do not stop there. - Inspect the runtime entrypoint, not just the UI code.
- Search for
eval,new Function,exec,spawn, and startup hooks. - Look inside static assets if the code mentions them.
- If the repo uses comments, weird strings, or base64-looking fragments, assume it may be encoded payload data until proven otherwise.
- Never run the project on your main machine before you understand the startup path.
Flow Diagram
server.js
↓
lib/serverStartup.js
↓
lib/startupLogs.js
↓
public/flags/*.svg
↓
HTML comment fragments
↓
base64 reconstruction
↓
eval(payload)
Closing thought
I went in expecting a take-home assessment.
What I found was a repo that used a clean-looking frontend as cover for a hidden payload loader. The lesson is simple: when something feels off, slow down and inspect the startup path. That is where malware likes to hide.
If you are job hunting right now, be careful. A polished assessment can still be malicious.
Also, currently open to Fullstack/Backend/AI roles.
Preferably the kind where the SVGs are not assembling malware payloads.
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