‘Fileless’ Malware Attacks Growing in Number and Sophistication

Not all malware arrives on your computers as a virus or some other type of code secreted in a file, but instead manifests itself as a corruption of system services that make your operating system do the dirty work. You may not have heard of a fileless malware attack, but despite its obscurity, it’s a real and serious threat. Furthermore, fileless malware makes up about 70 percent of executables that are unknown to reputation services, according to SentinelOne’s Enterprise Risk Index Report for the 2018 first half. This means that antivirus software that depends on matching a signature won’t find this malware. In many cases this is because the malware isn’t an executable file at all. Instead, it’s a process that’s delivered to a computer that takes over an existing service, such as Microsoft Windows PowerShell or another Windows service, which then loads software or follows commands that carry out the activities normally associated with malware.