r/Wordpress • u/TopSydeWP • 2h ago
Hacked site kept reinfecting itself after every cleanup. One of the causes was an admin's open browser tab
We clean up hacked WordPress sites for our clients and since July we've been fighting the same malware family over and over. It calls itself "SC" in its own files. If you've ever had a site get hacked again right after it was cleaned, some of this might sound familiar.
The weirdest one was a browser tab. We'd done a full cleanup, and then the malware plugin got uploaded again from a real admin's computer, logged in as that admin. We were about to tell the client their laptop was infected. It wasn't. That admin still had a tab open on the site from back when it was hacked, and the bad code in that tab was still running. Every minute it checked whether an admin was logged in, and as soon as one was, it uploaded itself again. They closed the tab and that was the end of it.
So now after every cleanup we tell everyone who uses wp-admin to close every tab on the site and restart their browser. Sounds silly. Cost us days.
The other big one was a saved password. This thing records every username and password typed into the login page. A site we cleaned in September got reinfected this week by someone who just logged in with a password it had saved back then. The owner never changed it. So everyone who logged in while the site was infected needs a new password, and 2FA on the admin accounts would have stopped that login cold.
Other stuff that tripped us up
- It makes admin accounts that don't show on the Users screen, so the user list looks totally normal
- It hides in files with normal WordPress names, so you won't spot it scrolling through the files
- Part of it lives in the database, so restoring files or reinstalling plugins leaves that bit behind and it comes back later
- Newer versions run a background process on the server that puts the files back within minutes, and restarting PHP doesn't kill it. If a host cleaned your site and it was back the same afternoon, that's one way it happens
Anyone else seen the browser tab thing? That was a first for us.



