For hackers, the equivalent of a shiny, well-built, turbocharged sports car is fileless or invisible malware. It’s so slick that it can masquerade in a computer network completely undetected for long lengths of time, heightening its chances of successfully racing through systems and causing conundrums. Fileless malware attacks rely on applications that already exist on a computer, forgoing dependence on malicious software.

Like sports cars, fileless or invisible malware comes in different models, so to speak.

“In some cases, [this] invisible malware lives only in memory, meaning there’s no file on your disks for your endpoint protection software to find. In other cases, invisible malware may live in your Basic Input/Output System (BIOS) where it can use one of a few tactics to attack you. In some cases, it may even appear as a firmware update where it replaces your existing firmware with a version that’s infected and nearly impossible to find or remove,” explains PC Magazine.

The attacks are particularly unnerving to try to identify and detect because they do not leave any traceable signature. This can allow the attacks to slip past signature-based or whitelist based security architecture. Fileless malware attacks are nearly 10 times more likely to succeed than traditional file-focused attacks, according to the Poneman Institute.

Small-to-medium sized businesses are expected to have the most trouble putting the brakes on these attacks, as some do not have the required IT support to offset advanced threats. One expert suggestion that’s gaining traction consists of replacing older servers containing critical data with newer ones that can combat fileless or invisible threats. Alternatively, or in addition, companies can transfer assets to cloud service providers, as they have more sophisticated cyber security dashboards.

Bottom line- move fast, before fileless malware overtakes you.

Get more on this story from Forbes.