If you clicked on an HBO Max ad on Reddit over the past week, you might want to check your computer for malware.
These so-called “ClickFix” attacks have quickly become one of the rising cybersecurity threats of 2026, and they’re getting both sneakier and compromising people’s devices with greater frequency. Until recently, ClickFix attacks were a rarity, capitalizing on people searching the web for quick tech fixes. They have since evolved into a massive international effort to hack into people’s computers.
The attacks involve fake websites, or legitimate websites that have been hacked, which display a message that appears to look like a CAPTCHA or an anti-bot checkbox. Once clicked, a prompt appears asking the user to perform a “check” to proceed, which gives instructions to copy and paste a string of text into the user’s Windows command prompt or Mac Terminal app.
As soon as the user hits return, they unwittingly and instantly install info-stealing malware on their computer, capable of immediately stealing their passwords, access to their logged-in accounts, and crypto wallets. Since the user is working in the computer’s terminal, which lets them interact directly with the operating system using text-based commands, many of these attacks evade antivirus and security defense tools.
Security researchers now say that the latest ClickFix campaign they’ve seen involved hackers posting fake ads on Reddit, linking to a page that looks like HBO Max but contains a ClickFix lure that tricks people into hacking themselves. The hackers compromised the official HBO Max’s account on Reddit that was then used to post hundreds of fake but real-looking adverts to the news-sharing site, according to security researchers at Hudson Rock and a thread on Reddit’s cybersecurity subreddit.
It’s unclear how many people clicked on these fake ads or how many were ultimately compromised as a result. Warner Brothers Discovery, which owns HBO, did not respond to a request for comment.
Reddit told TechCrunch it “recently learned that an HBO Max account authorized to run advertisements on Reddit was compromised and used to run ads containing malicious links,” and that the company locked the account and removed the ads. When asked, Reddit did not say how many users were targeted or clicked the malicious ads.
While it’s typical for developers to run one-line snippets of code in their computer’s terminal, it’s less common for regular users to use the Command Prompt or PowerShell in Windows, or the Terminal in macOS. Companies that run fleets of Windows computers can block access to these features across the entire domain to prevent them from being exploited, per security researcher Kevin Beaumont.
As noted by Ars Technica, a tool for Mac users called BlockBlock can also defend against attacks that try to trick Apple users into hacking themselves.
Updated with comment from Reddit.
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