Malware in firmware: how to exploit a false sense of security

When it comes to cyberthreats, we in ESET-LATAM Research often see ransomware, banking trojans (especially in my home country – Brazil), botnets or worms. As a consequence, other types of dangerous malware that run inconspicuously might get less of our attention; as is the case with firmware malware or bootkits.

Bootkits run before the OS loads and target OS components in order to modify or subvert their behavior. The fact that bootkits execute early in the system boot gives them the ability to remain stealthy and be persistent, surviving hard drive reformatting or OS reinstallation.

https://www.welivesecurity.com/2017/10/19/malware-firmware-exploit-sense-security/