12 Cores at 112°C: Claude Caught a Hidden Crypto Miner While Building a Mac Temperature App
- Level Beginner
- Setup~30 min (estimated)
- Evidence Some evidence
- CostNot stated in source
- No-codeNo
What they did
A Mac owner asked Claude to build a simple temperature monitor app. While checking sensor accuracy, Claude spotted a miner called xmrig using about 1175% CPU (roughly 12 cores) with the CPU peaking at 112°C. It traced the miner to /tmp, found a random-named startup item that had been there since Aug 29, and stopped to ask before killing or removing anything.
How it went
Screenshot of a Reddit r/claude post by u/UntilHEX shows Claude's report: xmrig at ~1175% CPU (~12 cores), CPU peaking at 112°C, running from /tmp/rigupdater and mining to pool.hashvault.sh, with a LaunchAgents startup item dated Aug 29. Claude did not remove anything without asking. Viral repost (9.5K likes). The prompt above is our own beginner version, not from the post
Worth knowing
- Screenshot of a Reddit r/claude post by u/UntilHEX shows Claude's report: xmrig at ~1175% CPU (~12 cores), CPU peaking at 112°C, running from /tmp/rigupdater and mining to pool.hashvault.sh, with a LaunchAgents startup item dated Aug 29. Claude did not remove anything without asking. Viral repost (9.5K likes). The prompt above is our own beginner version, not from the post.
Prompt
Cleaned version rewritten from the source — not a direct quote.
Help me check if my computer is secretly running a crypto miner or other malware. I'm not technical, so use plain language. Go one step at a time and wait for my answer before the next one: 1) Ask if I'm on Mac or Windows. 2) Walk me through opening Activity Monitor (Mac) or Task Manager (Windows) and sorting by CPU. 3) Ask me to close my apps, wait one minute, then send you a screenshot of the list. 4) Walk me through checking what starts up automatically, and ask for a screenshot. 5) Tell me which items look normal and which look suspicious, and why. Don't delete or kill anything yourself. If something looks bad, tell me to change my important passwords from a different device first.
Recommended
Try it in Grok Bot
- Copy the prompt (button below).
- Open Grok Bot chat and paste it. Replace any [bracketed] placeholders.
- Connect the listed tools (as needed) as connectors when Grok Bot asks.
- If the task repeats, ask: "Make this a daily routine."
Alternatives: the same prompt works in Claude, ChatGPT Agent, OpenClaw.
Set it up
Stack: Claude
- Read the original source for full context.
- Connect the tools your agent needs.
- Paste the prompt and replace [bracketed] placeholders.
- Run once manually and check the output before scheduling it.
Generic suggested steps, not from the source.
Evidence
Screenshot of a Reddit r/claude post by u/UntilHEX shows Claude's report: xmrig at ~1175% CPU (~12 cores), CPU peaking at 112°C, running from /tmp/rigupdater and mining to pool.hashvault.sh, with a LaunchAgents startup item dated Aug 29. Claude did not remove anything without asking. Viral repost (9.5K likes). The prompt above is our own beginner version, not from the post
Source: X · 2026-10-19 · Verified by us: not yet · Report broken or outdated