Sony has confirmed via Twitter that the malicious PSN messages causing PS4 consoles to crash has been fixed. Sony also clarified that the messages weren’t bricking consoles, but rather sending them into a infinite crash loop. If you are experiencing the infinite crash loop, the issue can be resolved in under 5 minutes.
We’ve since fixed the issue, and it wasn’t bricking consoles, just sending them into a crash loop that can be quickly fixed in under 5 minutes. Delete the message on the PS mobile app, go into Safe Mode, use Option 5, console back to normal. ^DB
— Ask PlayStation UK (@AskPS_UK) October 15, 2018
To fix the issue, Sony recommends deleting the malicious message using the PS Mobile app, and then using the PS4’s Safe Mode to rebuild the database (Option 5). The below video explains how to access Safe Mode: