Searched “Claude Mac” and Ran the Install Command From an Ad? How to Spot the Fake Claude Installer, and What to Do Now (2026)

The ad looked boring. That was the trick.

Its listed domain was bing.com, not some odd Claude lookalike. One click later you were on a polished “Download Claude for macOS” page with a one-line Terminal command and a friendly Copy button.

Security firm Push Security traced that chain in early October 2026 and named the technique “Adception.” Below is how the fake page works, how to tell whether your Mac actually ran the bad command, and the order of cleanup steps that matters if it did.

Jump to a Section

• What is the fake Claude installer spreading through Google ads?
• How can you tell the real Claude download from the fake one?
• Already pasted the command into Terminal? What to do first
• How do I check whether the malicious command actually ran?
• Why did Google approve an ad that led to malware?
• Installing Claude Without Touching a Search Ad
• Tips
• Warnings
• FAQ
• Sources

What is the fake Claude installer spreading through Google ads?

The fake Claude installer is a malicious copy of a Claude download page that, according to BleepingComputer’s October 9, 2026 report, was promoted through a Google search ad for “claude mac” and tricks Mac users into running a hidden Terminal command.

Push Security, which found it, calls the overall pattern “InstallFix.” It’s a cousin of the ClickFix scams that tell you to paste a “fix” into a terminal. Here the excuse isn’t an error message. It’s installation.

The path a victim followed had four hops, per Push Security’s write-up:

Hop sequence as documented by Push Security, October 2026. Domains are written with [.] so they can’t be clicked.

Push says the Bing link inside the ad carried a timestamp that decodes to October 5, 2026. So the campaign was live for at least a few days before the reports landed.

How can you tell the real Claude download from the fake one?

The real Claude for Mac download lives on claude.ai/download, and Anthropic’s Claude Code setup documentation (code.claude.com, checked October 12, 2026) lists exactly one curl command for macOS: curl -fsSL https://claude.ai/install.sh | bash.

The fake page showed that same command. Text on screen proves nothing.

When I compared the command Push captured from the fake Copy button with Anthropic’s version, I found that the first half was pure theater. It printed “Downloading Claude: https://claude.ai/install.sh” to the screen. The second half decoded a hidden Base64 address and piped a file from lake-90[.]com straight into zsh. So you’d see the right URL on the web page and the right URL in Terminal, while something else entirely ran.

That third row is the one people miss. Anthropic’s Claude Desktop help page says Mac users download the app from the Claude downloads page and open the file. Terminal only enters the picture for Claude Code, the developer tool.

If you wanted the chat app and a page asked you to paste a command, that’s your answer.

Already pasted the command into Terminal? What to do first

If you pasted a Claude “install” command from an ad-linked page into Terminal in October 2026, treat the Mac as compromised, because Push Security has not identified what the downloaded script delivers and Push’s earlier InstallFix research tied a similar fake Claude Code page to the Amatera infostealer, which takes browser-saved passwords, cookies, and session tokens.

Unknown payload means you plan for the bad case. Order matters here.

Method 1: Cut it off

1. Turn off Wi-Fi and unplug Ethernet on that Mac. This stops the script from sending more data out or pulling more pieces in.
2. Don’t type your Mac password into any prompt that appears. A surprise password box right after running a script is a classic way to grab Keychain access.
3. Leave the Mac on. Shutting down doesn’t undo anything and you’ll want it running to check what changed.

Method 2: Lock down accounts from a different device

1. Use your phone or another computer, not the affected Mac.
2. Change your email password first. Email is how every other reset reaches you.
3. Change your Apple Account, bank, and work passwords next, then anything saved in your browser.
4. Sign out of all sessions where the service offers it. Stolen cookies can keep someone logged in even after a password change.
5. Move crypto to a fresh wallet with a new seed phrase if a wallet extension or app was on that Mac.

Most people skip the session sign-out. Don’t.

How do I check whether the malicious command actually ran?

Your Mac’s zsh history file usually records every command typed or pasted into Terminal, so searching it for “base64” or “lake-90” shows whether the fake Claude command from the October 2026 campaign was actually run.

Method 3: Read your shell history

1. Open Terminal on the affected Mac. You can stay offline for this.
2. Run grep -n -i -e base64 -e lake-90 -e claude ~/.zsh_history and press Return.
3. Look for a line that starts with echo “Downloading Claude” and contains openssl base64. That’s the bad one.
4. Compare it to the official line, which is only curl -fsSL https://claude.ai/install.sh | bash.

If you only see the official command, you ran the real installer. Good news. If the history file is empty or missing, don’t read that as safe; some setups don’t save history and a script can wipe it.

Method 4: Look for things that start on their own

1. Open System Settings, then General, then Login Items & Extensions. Look under “Allow in the Background” for names you don’t recognize or that appeared the day you ran the command.
2. In Finder, press Shift-Command-G and visit ~/Library/LaunchAgents, then /Library/LaunchAgents and /Library/LaunchDaemons. Sort by Date Modified.
3. Note anything new rather than deleting it on a guess. Deleting the wrong file can break real apps.
4. Run a reputable Mac malware scanner once you’ve noted what you found.

Honestly, if the bad command is in your history and you have anything valuable on that Mac, backing up your documents and erasing the Mac is the cleanest end state. Apple’s Protect your Mac from malware guide covers what Gatekeeper and XProtect do. But a script piped straight into zsh never goes through the app-opening checks Gatekeeper is built around.

Why did Google approve an ad that led to malware?

Google’s ad review approved the malicious “claude mac” ad because its destination was a Bing search-result link, and Push Security reported in October 2026 that the payload page only appeared to visitors who followed the exact Google-to-Bing-to-hacked-site path.

Two filters did the hiding. The hacked retailer page only forwarded visitors with a Bing referrer and expected browser headers. Then the fake Claude page checked that you came from Google or Bing, and sent everyone else to a 404.

A reviewer or a scanner opening the link cold saw nothing wrong. Reading Push’s notes, I noticed that this is the part that should change your habits. A trusted domain on an ad tells you where the first hop goes. It says nothing about the last one.

Push also said it found several other domains using the same toolkit, which it tracks as AcSig, with the same Mac install command and fake installer layout. Blocking one domain won’t end this.

Installing Claude Without Touching a Search Ad

You don’t need an ad to find any Claude product. Here’s the short list of official routes listed in Anthropic’s own docs as of October 2026.

• Claude desktop app (Mac, Windows, Linux): type claude.ai/download into the address bar yourself. On a Mac it’s a normal download you open.
• Claude Code via Terminal: copy the command from Anthropic’s Claude Code setup page, then read it after pasting and before pressing Return.
• Claude Code via Homebrew: brew install --cask claude-code. No web page involved at all.
• Check it worked: open a new Terminal and run claude --version. A real install prints a version number.

If you’ve already installed Claude Code the right way, the next risk is what you plug into it. Our guide on checking Claude Code mods before you install them covers that, and the Plugin4Shell breakdown explains why agent plugins run with your permissions.

Tips

• Bookmark claude.ai/download once. Then you never need to search for it again.
• Scroll past the “Sponsored” label on any search for software downloads. Organic results to the vendor’s own domain are safer.
• After pasting any install command, press the left arrow and read the whole line before hitting Return. If it’s longer than what you saw on the page, stop.
• Keep browser-saved passwords to a minimum on machines where you install developer tools. A password manager with its own lock is harder to scrape.

Warnings

• Don’t visit claude-desk-code[.]com or lake-90[.]com “to see for yourself.” The cloaking means you’d likely get a 404, and if not, you’d get the payload.
• Don’t assume you’re safe because nothing visibly happened. Info-stealing scripts are designed to run quietly.
• Don’t reuse the old password anywhere after a suspected infection. Credential-stuffing tools try leaked passwords across many sites within hours.
• Push hasn’t published what the final payload does. Any article naming a specific malware family for this exact campaign is guessing.

FAQ

Is the official curl install command for Claude Code safe?

Yes, when it comes from Anthropic’s own setup page at code.claude.com and reads exactly curl -fsSL https://claude.ai/install.sh | bash. The danger is a fake page whose Copy button swaps in a longer command, so read the pasted line before pressing Return.

Does this fake Claude installer affect Windows users?

The Adception chain Push Security reported in October 2026 targeted Mac users searching for claude mac. Push’s earlier InstallFix research described fake Claude Code pages aimed at Windows too, so Windows users should follow the same rule and only copy commands from Anthropic’s own docs.

I clicked the ad but never pasted anything. Am I infected?

Probably not. In this campaign the page itself did not install anything; the harm came from pasting and running the copied command in Terminal. Clear your browser downloads, delete any file it saved, and skip the password reset unless you also ran a command.

Sources

• Push Security — Analysing a novel malicious redirect and cloaking technique (“Adception”)
• BleepingComputer — Hackers abuse Google Ads, Bing redirects to push Claude ClickFix attacks (October 9, 2026)
• Anthropic — Claude Code advanced setup (official install commands)
• Claude Help Center — Install Claude Desktop

Fact-checked against Push Security’s report, BleepingComputer, and Anthropic’s official install documentation as of October 12, 2026. Campaign domains change quickly; the official download addresses do not.