Hi everyone,
I’m looking for people who may have experienced the same thing, or anyone who can help me understand what happened.
I was browsing what I believed was the legitimate Python website when I encountered a fake CAPTCHA page. It instructed me to open Terminal on my Mac and paste a command to verify that I was human.
Unfortunately, I followed the instructions and executed the command. Looking back, it was a mistake. The command used a Base64-encoded payload, and after decoding it, I was told it appeared to download and execute a shell script from a suspicious domain.
Immediately after running it, a small window or prompt appeared asking for a password. I closed everything right away and did NOT enter my password.
Afterward, I noticed a suspicious file in my user folder with a name resembling com.Apple.fzylihcshhojvmnr. I also noticed Bash listed under Login Items.
Here’s what I’ve done so far:
- Changed my Apple ID and Google account passwords using another device.
- Ran a Malwarebytes scan, which reported no threats found.
- Had the suspicious file quarantined and deleted it.
- Restarted my Mac and checked running processes, network connections, and LaunchAgents/LaunchDaemons.
- Investigated several unfamiliar-looking processes that turned out to be legitimate macOS components.
My Mac is an Intel MacBook Pro running macOS. I also use it to access a VPS over SSH, so I’m concerned about whether my SSH private key, browser sessions, or other credentials could have been exposed.
My questions:
1 Has anyone encountered this specific fake CAPTCHA / Terminal attack on macOS?
2 Does the password prompt sound familiar? Could it have been part of the malware’s attempt to obtain elevated privileges?
3 Has anyone seen a suspicious file or Login Item with a name like com.Apple.fzylihcshhojvmnr?
4 Is there a known way to determine what the downloaded script actually did, or whether it established persistence?
5 Given that Malwarebytes found nothing afterward, would you consider a clean macOS reinstall necessary, especially on a machine used to administer servers?
I’m not assuming the Mac is clean just because the scan came back negative. I’d really appreciate firsthand experiences, technical analysis, or links to reports of similar attacks.
I can share the original command or the decoded script if I can recover it safely
Thanks!