Rick is getting an error message that he's lost his Wi-Fi connection. Leo says it's a common issue with Wi-Fi. It's not malware because the last thing malware would want is to get him offline. Malware these days is about making money off of him, and that means it has a vested interest in keeping him online.
When Rick rebooted, the Wi-Fi light on his router wasn't on. He did a system repair which fixed it. Leo says that the router may have chosen a congested channel and as such, he may be just getting knocked off. It may also be an issue with a recent update.