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Bashar V I
Bashar V I

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🚨 Freelancers beware: how a suspicious “Node.js bug fix” invite helped me spot a possible malware dropper on Upwork

Screen shot of upwork job postToday I received an Upwork job invite titled
“Experienced Node.js Coder Needed for Bug Fix”
with a tempting $760 fixed price and a Dropbox link to the code.

It looked normal at first, but a few details didn’t sit right:

  • đź’¸ Unrealistic budget for a simple bug fix.
  • 📦 The client insisted I download and run a ZIP immediately to “see the error.”
  • 👤 Profile not payment verified and brand-new.

Instead of running it, I inspected the archive without executing anything.
Here’s what I found:

  • node/helpers/css.js reads a “CSS” file (public/css/types.txt) and runs it with eval() only on Windows.
  • types.txt isn’t CSS at all—it’s obfuscated JavaScript that
  • extracts hidden ZIPs (js.zip, node.zip, i.zip),and silently spawns Windows executables via cmd.exe /c start.
  • The project even bundles a 7-Zip binary so it can unpack those hidden files locally.**_

That pattern—obfuscation + hidden zips + detached .exe launch—is exactly how a dropper/backdoor works.

I’ve flagged the job and reported it to @Upwork Trust & Safety so they can warn others.

🔑 Takeaways for fellow freelancers

  • Never run code from strangers without first looking inside (even on trusted platforms).
  • Watch for red flags: unverified payment, big payout for trivial work, pressure to run code immediately.
  • If something feels off, stop, inspect, and report.

Stay safe and keep each other safe.

Upwork #freelance #security #NodeJS #infosec #webdev #malware

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