Can Anti-malware software stop it?
Not reliably, even updated versions. It’s pot luck. Like a lot of recent ransomware, Zepto runs as a script in the most minimal way possible and then downloads the business end of the malware. By the time that is on a system, it is too late to stop something from happening. Good anti-ransomware will notice the unusual behaviour (accessing lots of files and their increased file entropy as encryption commences) and step in. But this requires security software has been programmed specifically to understand this type of behaviour.